diff --git a/nether/LICENSE.txt b/nether/LICENSE.txt
new file mode 100644
index 00000000..c43a1797
--- /dev/null
+++ b/nether/LICENSE.txt
@@ -0,0 +1,2 @@
+GPLv3 (lkloel's version)
+MIT for the changes
diff --git a/nether/README.md b/nether/README.md
new file mode 100644
index 00000000..a2a9712b
--- /dev/null
+++ b/nether/README.md
@@ -0,0 +1,15 @@
+For a description of this Minetest mod, please refer to the forum topic:
+https://forum.minetest.net/viewtopic.php?f=9&t=10265
+
+
+TODO:
+* Find a way to get the perlin noise inside [-1; 1] or use another noise
+* Add some node which containing items to the simple pyramid "buildings"
+* Change the sky background, fog, etc. in the nether
+* Improve the guide formspec.
+  Writing it in Markdown would be nice.
+  These could be useful:
+  * https://forum.minetest.net/viewtopic.php?t=23855
+    Minetest Bedrock Markup Language
+  * https://github.com/mpeterv/markdown
+    Markdown to HTML converter; Minetest formspecs support HTML
diff --git a/nether/modpack.txt b/nether/modpack.txt
new file mode 100644
index 00000000..573541ac
--- /dev/null
+++ b/nether/modpack.txt
@@ -0,0 +1 @@
+0
diff --git a/nether/nether/crafting.lua b/nether/nether/crafting.lua
new file mode 100644
index 00000000..73e1b8f7
--- /dev/null
+++ b/nether/nether/crafting.lua
@@ -0,0 +1,253 @@
+minetest.register_craft({
+	output = "nether:fim",
+	recipe = {
+		{"nether:shroom_head"},
+		{"nether:fruit_no_leaf"},
+		{"nether:shroom_head"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:fruit_leaves",
+	recipe = {
+		{"nether:fruit_leaf", "nether:fruit_leaf", "nether:fruit_leaf"},
+		{"nether:fruit_leaf", "nether:fruit_leaf", "nether:fruit_leaf"},
+		{"nether:fruit_leaf", "nether:fruit_leaf", "nether:fruit_leaf"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:pick_mushroom",
+	recipe = {
+		{"nether:shroom_head", "nether:shroom_head", "nether:shroom_head"},
+		{"", "nether:shroom_stem", ""},
+		{"", "nether:shroom_stem", ""},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:pick_wood",
+	recipe = {
+		{"nether:wood_cooked", "nether:wood_cooked", "nether:wood_cooked"},
+		{"", "group:stick", ""},
+		{"", "group:stick", ""},
+	}
+})
+
+for _,m in pairs({"netherrack", "netherrack_blue", "white"}) do
+	local input = "nether:"..m
+
+	minetest.register_craft({
+		output = "nether:pick_"..m,
+		recipe = {
+			{input, input, input},
+			{"", "group:stick", ""},
+			{"", "group:stick", ""},
+		}
+	})
+
+	minetest.register_craft({
+		output = "nether:axe_"..m,
+		recipe = {
+			{input, input},
+			{input, "group:stick"},
+			{"", "group:stick"},
+		}
+	})
+
+	minetest.register_craft({
+		output = "nether:sword_"..m,
+		recipe = {
+			{input},
+			{input},
+			{"group:stick"},
+		}
+	})
+
+	minetest.register_craft({
+		output = "nether:shovel_"..m,
+		recipe = {
+			{input},
+			{"group:stick"},
+			{"group:stick"},
+		}
+	})
+end
+
+minetest.register_craft({
+	output = "nether:netherrack_brick 4",
+	recipe = {
+		{"nether:netherrack", "nether:netherrack"},
+		{"nether:netherrack", "nether:netherrack"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:netherrack_brick_black 4",
+	recipe = {
+		{"nether:netherrack_black", "nether:netherrack_black"},
+		{"nether:netherrack_black", "nether:netherrack_black"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:netherrack_brick_blue 4",
+	recipe = {
+		{"nether:netherrack_blue", "nether:netherrack_blue"},
+		{"nether:netherrack_blue", "nether:netherrack_blue"},
+	}
+})
+
+minetest.register_craft({
+	output = "default:furnace",
+	recipe = {
+		{"nether:netherrack_brick", "nether:netherrack_brick", "nether:netherrack_brick"},
+		{"nether:netherrack_brick", "", "nether:netherrack_brick"},
+		{"nether:netherrack_brick", "nether:netherrack_brick", "nether:netherrack_brick"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:extractor",
+	recipe = {
+		{"nether:netherrack_brick", "nether:blood_top_cooked", "nether:netherrack_brick"},
+		{"nether:blood_cooked", "nether:shroom_stem", "nether:blood_cooked"},
+		{"nether:netherrack_brick", "nether:blood_stem_cooked", "nether:netherrack_brick"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:wood 4",
+	recipe = {
+		{"nether:blood_stem"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:wood_empty 4",
+	recipe = {
+		{"nether:blood_stem_empty"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:stick 4",
+	recipe = {
+		{"nether:wood_empty"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:torch",
+	recipe = {
+		{"nether:bark"},
+		{"group:stick"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:forest_wood",
+	recipe = {
+		{"nether:forest_planks", "nether:forest_planks", "nether:forest_planks"},
+		{"nether:forest_planks", "", "nether:forest_planks"},
+		{"nether:forest_planks", "nether:forest_planks", "nether:forest_planks"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:forest_planks 8",
+	recipe = {
+		{"nether:forest_wood"},
+	}
+})
+
+minetest.register_craft({
+	output = "nether:forest_planks 7",
+	recipe = {
+		{"nether:tree"},
+	},
+})
+
+local sound_allowed = true
+minetest.register_on_craft(function(itemstack, player, old_craft_grid, craft_inv)
+	if itemstack:get_name() ~= "nether:forest_planks"
+	or itemstack:get_count() ~= 7 then
+		return
+	end
+	local tree
+	for i = 1,9 do
+		if old_craft_grid[i]:get_name() == "nether:tree" then
+			tree = i
+			break
+		end
+	end
+	if not tree then	-- do nth if theres no tree
+		return
+	end
+	local rdif = math.random(-1,1)	-- add a bit randomness
+	local barkstack = ItemStack("nether:bark "..4-rdif)
+	local inv = player:get_inventory()
+	if not inv:room_for_item("main", barkstack) then	-- disallow crafting if there's not enough free space
+		craft_inv:set_list("craft", old_craft_grid)
+		itemstack:set_name("")
+		return
+	end
+	itemstack:set_count(7+rdif)
+	inv:add_item("main", barkstack)
+	if not sound_allowed then	-- avoid playing the sound multiple times, e.g. when middle mouse click
+		return
+	end
+	minetest.sound_play("default_wood_footstep", {pos=player:get_pos(),  gain=0.25})
+	sound_allowed = false
+	minetest.after(0, function()
+		sound_allowed = true
+	end)
+end)
+
+minetest.register_craft({
+	output = "default:paper",
+	recipe = {
+		{"nether:grass_dried", "nether:grass_dried", "nether:grass_dried"},
+	}
+})
+
+
+minetest.register_craft({
+	type = "cooking",
+	output = "default:coal_lump",
+	recipe = "nether:tree",
+})
+
+minetest.register_craft({
+	type = "cooking",
+	output = "nether:grass_dried",
+	recipe = "nether:grass",
+})
+
+minetest.register_craft({
+	type = "cooking",
+	output = "nether:pearl",
+	recipe = "nether:fim",
+})
+
+minetest.register_craft({
+	type = "cooking",
+	output = "nether:hotbed",
+	recipe = "nether:blood_extracted",
+})
+
+for  _,i in ipairs({"nether:blood", "nether:blood_top", "nether:blood_stem", "nether:wood"}) do
+	local cooked = i.."_cooked"
+
+	minetest.register_craft({
+		type = "cooking",
+		output = cooked,
+		recipe = i,
+	})
+
+	minetest.register_craft({
+		type = "fuel",
+		recipe = cooked,
+		burntime = 30,
+	})
+end
diff --git a/nether/nether/furnace.lua b/nether/nether/furnace.lua
new file mode 100644
index 00000000..577d7374
--- /dev/null
+++ b/nether/nether/furnace.lua
@@ -0,0 +1,346 @@
+-- minetest time speed
+local time_speed = tonumber(minetest.settings:get("time_speed"))
+if not time_speed then
+	time_speed = 1
+else
+	time_speed = time_speed/72
+end
+
+local function get_date()
+	return os.date("%y %d %H %M %S")
+end
+
+-- returns the time difference in seconds
+local function get_timediff(d1, d2)
+	local d = string.split(d1, " ")
+	for n,i in pairs(string.split(d2, " ")) do
+		d[n] = i-d[n]
+	end
+	local secs = 0
+	local y,d,h,m,s = unpack(d)
+	if s ~= 0 then
+		secs = secs+s
+	end
+	if m ~= 0 then
+		secs = secs+m*60
+	end
+	if h ~= 0 then
+		secs = secs+h*3600	-- 60*60
+	end
+	if d ~= 0 then
+		secs = secs+d*86400	-- 60*60*24
+	end
+	if y ~= 0 then
+		secs = secs+y*31557600	-- 60*60*24*365.25
+	end
+	--secs = math.floor(secs+0.5)
+	if secs < 0 then
+		minetest.log("action", "play warzone2100?")
+	end
+	return secs*time_speed
+end
+
+-- copied from older default furnace code and edited a bit
+
+function nether.get_furnace_active_formspec(pos, percent)
+	local formspec =
+		"size[8,9]"..
+		"image[2,2;1,1;default_furnace_fire_bg.png^[lowpart:"..
+		(100-percent)..":default_furnace_fire_fg.png]"..
+		"list[current_name;fuel;2,3;1,1;]"..
+		"list[current_name;src;2,1;1,1;]"..
+		"list[current_name;dst;5,1;2,2;]"..
+		"list[current_player;main;0,5;8,4;]"
+	return formspec
+end
+
+nether.furnace_inactive_formspec =
+	"size[8,9]"..
+	"image[2,2;1,1;default_furnace_fire_bg.png]"..
+	"list[current_name;fuel;2,3;1,1;]"..
+	"list[current_name;src;2,1;1,1;]"..
+	"list[current_name;dst;5,1;2,2;]"..
+	"list[current_player;main;0,5;8,4;]"
+
+minetest.register_node("nether:furnace", {
+	description = "Furnace",
+	tiles = {"default_furnace_top.png", "default_furnace_bottom.png", "default_furnace_side.png",
+		"default_furnace_side.png", "default_furnace_side.png", "default_furnace_front.png"},
+	paramtype2 = "facedir",
+	groups = {cracky=2},
+	legacy_facedir_simple = true,
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("formspec", nether.furnace_inactive_formspec)
+		meta:set_string("infotext", "Furnace")
+		local inv = meta:get_inventory()
+		inv:set_size("fuel", 1)
+		inv:set_size("src", 1)
+		inv:set_size("dst", 4)
+	end,
+	can_dig = function(pos,player)
+		local meta = minetest.get_meta(pos);
+		local inv = meta:get_inventory()
+		if not inv:is_empty("fuel") then
+			return false
+		elseif not inv:is_empty("dst") then
+			return false
+		elseif not inv:is_empty("src") then
+			return false
+		end
+		return true
+	end,
+	allow_metadata_inventory_put = function(pos, listname, index, stack, player)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("last_active", get_date())
+		local inv = meta:get_inventory()
+		if listname == "fuel" then
+			if minetest.get_craft_result({method="fuel",width=1,items={stack}}).time ~= 0 then
+				if inv:is_empty("src") then
+					meta:set_string("infotext","Furnace is empty")
+				end
+				return stack:get_count()
+			else
+				return 0
+			end
+		elseif listname == "src" then
+			return stack:get_count()
+		elseif listname == "dst" then
+			return 0
+		end
+	end,
+	allow_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("last_active", get_date())
+		local inv = meta:get_inventory()
+		local stack = inv:get_stack(from_list, from_index)
+		if to_list == "fuel" then
+			if minetest.get_craft_result({method="fuel",width=1,items={stack}}).time ~= 0 then
+				if inv:is_empty("src") then
+					meta:set_string("infotext","Furnace is empty")
+				end
+				return count
+			else
+				return 0
+			end
+		elseif to_list == "src" then
+			return count
+		elseif to_list == "dst" then
+			return 0
+		end
+	end,
+})
+
+minetest.register_node("nether:furnace_active", {
+	description = "Furnace",
+	tiles = {
+		"default_furnace_top.png",
+		"default_furnace_bottom.png",
+		"default_furnace_side.png",
+		"default_furnace_side.png",
+		"default_furnace_side.png",
+		{
+			image = "default_furnace_front_active.png",
+			backface_culling = false,
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 16,
+				aspect_h = 16,
+				length = 1.5
+			},
+		}
+	},
+	paramtype2 = "facedir",
+	light_source = 8,
+	drop = "nether:furnace",
+	groups = {cracky=2, not_in_creative_inventory=1,hot=1},
+	legacy_facedir_simple = true,
+	is_ground_content = false,
+	sounds = default.node_sound_stone_defaults(),
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("formspec", nether.furnace_inactive_formspec)
+		meta:set_string("infotext", "Furnace");
+		local inv = meta:get_inventory()
+		inv:set_size("fuel", 1)
+		inv:set_size("src", 1)
+		inv:set_size("dst", 4)
+	end,
+	can_dig = function(pos,player)
+		local meta = minetest.get_meta(pos);
+		local inv = meta:get_inventory()
+		if not inv:is_empty("fuel") then
+			return false
+		elseif not inv:is_empty("dst") then
+			return false
+		elseif not inv:is_empty("src") then
+			return false
+		end
+		return true
+	end,
+	allow_metadata_inventory_put = function(pos, listname, index, stack, player)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("last_active", get_date())
+		local inv = meta:get_inventory()
+		if listname == "fuel" then
+			if minetest.get_craft_result({method="fuel",width=1,items={stack}}).time ~= 0 then
+				if inv:is_empty("src") then
+					meta:set_string("infotext","Furnace is empty")
+				end
+				return stack:get_count()
+			else
+				return 0
+			end
+		elseif listname == "src" then
+			return stack:get_count()
+		elseif listname == "dst" then
+			return 0
+		end
+	end,
+	allow_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("last_active", get_date())
+		local inv = meta:get_inventory()
+		local stack = inv:get_stack(from_list, from_index)
+		if to_list == "fuel" then
+			if minetest.get_craft_result({method="fuel",width=1,items={stack}}).time ~= 0 then
+				if inv:is_empty("src") then
+					meta:set_string("infotext","Furnace is empty")
+				end
+				return count
+			else
+				return 0
+			end
+		elseif to_list == "src" then
+			return count
+		elseif to_list == "dst" then
+			return 0
+		end
+	end,
+})
+
+local function swap_node(pos,name)
+	local node = minetest.get_node(pos)
+	if node.name == name then
+		return
+	end
+	node.name = name
+	minetest.swap_node(pos,node)
+end
+
+minetest.register_abm({
+	nodenames = {"nether:furnace","nether:furnace_active"},
+	interval = 1.0,
+	chance = 1,
+	action = function(pos)
+		local meta = minetest.get_meta(pos)
+		if meta:get_string("timedif") == "" then
+			meta:set_float("timedif", 0.0)
+		end
+
+		-- lag shouldn't control the furnace speed
+		local current_time = get_date()
+		local last_time = meta:get_string("last_active")
+		if last_time == "" then
+			meta:set_string("last_active", current_time)
+			return
+		end
+		if last_time == current_time then
+			return
+		end
+
+		local timediff = get_timediff(last_time, current_time)+meta:get_string("timedif")
+		local times = math.floor(timediff)
+		meta:set_string("last_active", current_time)
+		meta:set_float("timedif", timediff-times)
+
+
+		for _ = 1,times do
+			for _,name in pairs({
+					"fuel_totaltime",
+					"fuel_time",
+					"src_totaltime",
+					"src_time",
+			}) do
+				if meta:get_string(name) == "" then
+					meta:set_float(name, 0.0)
+				end
+			end
+			local inv = meta:get_inventory()
+			local srclist = inv:get_list("src")
+			local cooked = nil
+			local aftercooked
+
+			if srclist then
+				cooked, aftercooked = minetest.get_craft_result({method = "cooking", width = 1, items = srclist})
+			end
+
+			local was_active = false
+
+			if meta:get_float("fuel_time") < meta:get_float("fuel_totaltime") then
+				was_active = true
+				meta:set_float("fuel_time", meta:get_float("fuel_time") + 1)
+				meta:set_float("src_time", meta:get_float("src_time") + 1)
+				if cooked
+				and cooked.item
+				and meta:get_float("src_time") >= cooked.time then
+					-- check if there's room for output in "dst" list
+					if inv:room_for_item("dst",cooked.item) then
+						-- Put result in "dst" list
+						inv:add_item("dst", cooked.item)
+						-- take stuff from "src" list
+						inv:set_stack("src", 1, aftercooked.items[1])
+					--~ else
+						--print("Could not insert '"..cooked.item:to_string().."'")
+					end
+					meta:set_string("src_time", 0)
+				end
+			end
+
+			if meta:get_float("fuel_time") < meta:get_float("fuel_totaltime") then
+				local percent = math.floor(meta:get_float("fuel_time") /
+						meta:get_float("fuel_totaltime") * 100)
+				meta:set_string("infotext","Furnace active: "..percent.."%")
+				swap_node(pos,"nether:furnace_active")
+				meta:set_string("formspec",nether.get_furnace_active_formspec(pos, percent))
+				return
+			end
+
+			local fuel = nil
+			local afterfuel
+			local cooked = nil
+			local fuellist = inv:get_list("fuel")
+			local srclist = inv:get_list("src")
+
+			if srclist then
+				cooked = minetest.get_craft_result({method = "cooking", width = 1, items = srclist})
+			end
+			if fuellist then
+				fuel, afterfuel = minetest.get_craft_result({method = "fuel", width = 1, items = fuellist})
+			end
+
+			if not fuel or fuel.time <= 0 then
+				meta:set_string("infotext","Furnace out of fuel")
+				swap_node(pos,"nether:furnace")
+				meta:set_string("formspec", nether.furnace_inactive_formspec)
+				return
+			end
+
+			if cooked.item:is_empty() then
+				if was_active then
+					meta:set_string("infotext","Furnace is empty")
+					swap_node(pos,"nether:furnace")
+					meta:set_string("formspec", nether.furnace_inactive_formspec)
+				end
+				return
+			end
+
+			meta:set_string("fuel_totaltime", fuel.time)
+			meta:set_string("fuel_time", 0)
+
+			inv:set_stack("fuel", 1, afterfuel.items[1])
+		end
+	end,
+})
diff --git a/nether/nether/guide.lua b/nether/nether/guide.lua
new file mode 100644
index 00000000..c90f3204
--- /dev/null
+++ b/nether/nether/guide.lua
@@ -0,0 +1,411 @@
+local cube = minetest.inventorycube
+
+-- the content of the guide
+local guide_infos = {
+	{
+		description = "Mushrooms",
+		{"text", "Nether mushrooms can be found on the nether's ground and\n"..
+			"on netherrack soil, it can be dug by hand."},
+		{"image", {1, 1, "riesenpilz_nether_shroom_side.png"}},
+		{"y", 0.2},
+		{"text", "If you drop it without holding the fast key, you can split it into its stem and head:"},
+		{"image", {1, 1, "nether_shroom_top.png", 1}},
+		{"image", {1, 1, "nether_shroom_stem.png"}},
+		{"y", 0.1},
+		{"text", "You can get more mushrooms by using a netherrack soil:\n"..
+			"1. search a dark place and, if necessary, place netherrack with air about it\n"..
+			"2. right click with cooked blood onto the netherrack to make it soiled\n"..
+			"3. right click onto the netherrack soil with a nether mushroom head to add some spores\n"..
+			"4. dig the mushroom which grew after some time to make place for another one"},
+		{"image", {1, 1, "riesenpilz_nether_shroom_side.png", 6, 0.12}},
+		{"y", 1},
+		{"image", {1, 1, "nether_netherrack.png^nether_netherrack_soil.png", 1.8}},
+		{"image", {1, 1, "nether_hotbed.png", 1.3, -0.4}},
+		{"image", {1, 1, "nether_netherrack.png^nether_netherrack_soil.png", 3.6}},
+		{"image", {1, 1, "nether_shroom_top.png", 3.1, -0.5}},
+		{"image", {1, 1, "nether_netherrack.png^nether_netherrack_soil.png", 6}},
+		{"image", {1, 1, "nether_netherrack.png"}},
+	},
+	{
+		description = "Tools",
+		{"text", "You can craft 5 kinds of tools in the nether,\n"..
+			"which (except the mushroom pick) require sticks to be crafted:"},
+		{"image", {1, 1, "nether_pick_mushroom.png"}},
+		{"y", 0.1},
+		{"text", "strength : 1\n"..
+			"The mushroom pick needs mushroom stems and heads to be crafted."},
+		{"image", {1, 1, "nether_pick_wood.png"}},
+		{"y", 0.1},
+		{"text", "strength : 2\n"..
+			"The nether wood pick can be crafted with cooked nether blood wood."},
+		{"image", {1, 1, "nether_axe_netherrack.png", 1.5}},
+		{"image", {1, 1, "nether_shovel_netherrack.png", 3}},
+		{"image", {1, 1, "nether_sword_netherrack.png", 4.5}},
+		{"image", {1, 1, "nether_pick_netherrack.png"}},
+		{"y", 0.1},
+		{"text", "strength : 3\n"..
+			"The red netherrack tools can be crafted with usual netherrack."},
+		{"image", {1, 1, "nether_axe_netherrack_blue.png", 1.5}},
+		{"image", {1, 1, "nether_shovel_netherrack_blue.png", 3}},
+		{"image", {1, 1, "nether_sword_netherrack_blue.png", 4.5}},
+		{"image", {1, 1, "nether_pick_netherrack_blue.png"}},
+		{"y", 0.1},
+		{"text", "strength : 3\n"..
+			"The blue netherrack tools can be crafted with blue netherrack."},
+		{"image", {1, 1, "nether_axe_white.png", 1.5}},
+		{"image", {1, 1, "nether_shovel_white.png", 3}},
+		{"image", {1, 1, "nether_sword_white.png", 4.5}},
+		{"image", {1, 1, "nether_pick_white.png"}},
+		{"y", 0.1},
+		{"text", "strength : 3\n"..
+			"The siwtonic tools can be crafted with the siwtonic ore."},
+	},
+	{
+		description = "Blood structures",
+		{"text", "You can find blood structures on the ground and\n"..
+			"dig their nodes even with the bare hand."},
+		{"y", 0.5},
+		{"text", "One contains 4 kinds of blocks :"},
+		{"image", {1, 1, cube("nether_blood.png"), 1}},
+		{"image", {1, 1,
+			cube("nether_blood_top.png",
+				"nether_blood.png^nether_blood_side.png",
+				"nether_blood.png^nether_blood_side.png"),
+			2}},
+		{"image", {1, 1, "nether_fruit.png", 3}},
+		{"image", {1, 1, cube("nether_blood_stem_top.png",
+			"nether_blood_stem.png", "nether_blood_stem.png")}},
+		{"y", 0.1},
+		{"text", "Blood stem, blood, blood head and nether fruit"},
+		{"y", 0.1},
+		{"text", "You can craft 4 blood wood with the stem :"},
+		{"image", {1, 1, cube("nether_wood.png")}},
+		{"y", 0.1},
+		{"text", "The 4 blood nodes can be cooked and, except\n"..
+			"blood wood, their blood can be extracted."},
+	},
+	{
+		description = "Fruits",
+		{"text", "You can find the nether fruits on blood structures\n"..
+			"and dig them even with the bare hand."},
+		{"image", {1, 1, "nether_fruit.png"}},
+		{"text", "Eating it will make you lose life but\n"..
+			"it might feed you and give you blood :"},
+		{"image", {1, 1, "nether_blood_extracted.png"}},
+		{"y", 0.2},
+		{"text", "If you eat it at the right place inside a portal,\n"..
+			"you will teleport instead of getting blood."},
+		{"y", 0.2},
+		{"text", "If you drop it without holding the fast key,\n"..
+			"you can split it into its fruit and leaf:"},
+		{"image", {1, 1, "nether_fruit_leaf.png", 1}},
+		{"image", {1, 1, "nether_fruit_no_leaf.png"}},
+		{"y", 0.2},
+		{"text", "Craft a fruit leave block out of 9 fruit leaves\n"..
+			"The fruit can be used to craft a nether pearl."},
+		{"image", {1, 1, cube("nether_fruit_leaves.png")}},
+		{"y", 0.2},
+		{"text", "A fruit leaves block"},
+	},
+	{
+		description = "Cooking",
+		{"text", "To get a furnace you need to dig at least 8 netherrack bricks.\n"..
+			"They can be found at pyramid like constructions and require at least\n"..
+			"a strength 1 nether pick to be dug.\n"..
+			"To craft the furnace, use the netherrack bricks like cobble:"},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 0.5}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 1}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png")}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 1}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png")}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 0.5}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 1}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png")}},
+		{"y", 0.2},
+		{"text", "To begin cooking stuff, you can use a mushroom or fruit.\n"..
+			"After that it's recommended to use cooked blood nodes."},
+		{"y", 0.1},
+		{"text", "Some nether items can be cooked:"},
+		{"image", {1, 1, cube("nether_blood_stem_top_cooked.png",
+			"nether_blood_stem_cooked.png", "nether_blood_stem_cooked.png"),
+			0.35}},
+		{"image", {1, 1, cube("nether_blood_cooked.png"), 1.6}},
+		{"image", {1, 1,
+			cube("nether_blood_top_cooked.png",
+				"nether_blood_cooked.png^nether_blood_side_cooked.png",
+				"nether_blood_cooked.png^nether_blood_side_cooked.png"),
+			2.9}},
+		{"image", {1, 1, cube("nether_wood_cooked.png"), 4.3}},
+		{"y", 1.2},
+		{"text", "Some cooked blood stem, cooked blood,\n"..
+			"cooked blood head and cooked blood wood,"},
+		{"image", {1, 1, "nether_hotbed.png", 0.3}},
+		{"image", {1, 1, "nether_pearl.png", 2}},
+		{"y", 1.2},
+		{"text", "Some cooked extracted blood and a nether pearl"},
+	},
+	{
+		description = "Extractors",
+		{"text", "Here you can find out information about the nether extractor."},
+		{"y", 0.2},
+		{"text", "Here you can see its craft recipe:"},
+		{"image", {0.5, 0.5, cube("nether_blood_top_cooked.png",
+			"nether_blood_cooked.png^nether_blood_side_cooked.png",
+			"nether_blood_cooked.png^nether_blood_side_cooked.png"), 0.5}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 1}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png")}},
+		{"image", {0.5, 0.5, cube("nether_blood_extractor.png"), 2.5}},
+		{"image", {0.5, 0.5, "nether_shroom_stem.png", 0.5}},
+		{"image", {0.5, 0.5, cube("nether_blood_cooked.png"), 1}},
+		{"image", {0.5, 0.5, cube("nether_blood_cooked.png")}},
+		{"image", {0.5, 0.5, cube("nether_blood_stem_top_cooked.png",
+			"nether_blood_stem_cooked.png", "nether_blood_stem_cooked.png"),
+			0.5}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png"), 1}},
+		{"image", {0.5, 0.5, cube("nether_netherrack_brick.png")}},
+		{"y", 0.2},
+		{"text", "Extract blood from the blood nodes you get from the blood structures.\n"..
+			"You can also get blood with a nether fruit."},
+		{"y", 0.2},
+		{"text", "So you can use it:\n"..
+			"1. place it somewhere\n"..
+			"2. place blood blocks next to it (4 or less)\n"..
+			"3. right click with extracted blood onto it to power it\n"..
+			"4. take the new extracted blood and dig the extracted nodes"},
+		{"y", 0.2},
+		{"text", "Example (view from the top):"},
+		{"y", 0.88},
+		{"image", {1, 1, "nether_blood_stem_top.png", 0.82, -0.88}},
+		{"image", {1, 1, "nether_blood.png", 1.63}},
+		{"image", {1, 1, "nether_blood_extractor.png", 0.82}},
+		{"image", {1, 1, "nether_blood_stem_top_empty.png", 3.82, -0.88}},
+		{"image", {1, 1, "nether_blood_empty.png", 4.63}},
+		{"image", {1, 1, "nether_blood_empty.png", 3.001}},
+		{"image", {1, 1, "nether_blood_extractor.png", 3.82}},
+		{"image", {1, 1, "nether_blood.png"}},
+		{"image", {1, 1, "nether_blood.png", 0.82, -0.12}},
+		{"image", {1, 1, "nether_blood_empty.png", 3.82, -0.12}},
+		{"y", 1.2},
+		{"text", "The empty blood stem can be crafted into empty nether wood,\n"..
+			"which can be crafted into nether sticks."},
+	},
+	{
+		description = "Ores",
+		{"text", "You can find 5 types of ores:"},
+		{"image", {1, 1, cube("nether_netherrack_black.png"), 4}},
+		{"image", {1, 1, cube("nether_netherrack.png")}},
+		{"y", 0.2},
+		{"text", "The red netherrack is generated like stone.\n"..
+			"The black netherrack is generated like gravel.\n"..
+			"Both require at least a strength 2 nether pick to be dug."},
+		{"image", {1, 1, cube("nether_white.png"), 4}},
+		{"image", {1, 1, cube("nether_netherrack_blue.png")}},
+		{"y", 0.2},
+		{"text", "The blue netherrack is generated like diamond ore.\n"..
+			"The siwtonic ore is generated like mese blocks.\n"..
+			"Both require at least a strength 3 nether pick to be dug."},
+		{"image", {1, 1, cube("nether_netherrack_tiled.png"), 4}},
+		{"image", {1, 1, cube("glow_stone.png")}},
+		{"y", 0.2},
+		{"text", "Glow stone can be used for lighting.\n"..
+			"Tiled netherrack is generated like coal ore.\n"..
+			"Glow stone requires at least a strength 1 pick to be dug.\n"..
+			"Dig tiled netherrack with at least a level 2 pickaxe."},
+	},
+	{
+		description = "Vines",
+		{"text", "Feed nether vines with blood.\n"..
+			"Dig them with anything."},
+		{"image", {1, 1, "nether_vine.png"}},
+		{"y", 0.2},
+		{"text", "Grow nether child by placing\n"..
+			"placing it to a dark place onto a\n"..
+			"blood structure head node."},
+		{"image", {1, 1, "nether_sapling.png"}},
+		{"y", -0.10},
+		{"image", {1, 1, "nether_blood.png^nether_blood_side.png"}},
+	},
+	{
+		description = "Pearls",
+		{"text", "The nether pearl can be used to teleport by throwing it.\n"..
+			"Here is how to get one :"},
+		{"y", 0.2},
+		{"text", "First of all craft 2 mushroom heads and 1 nether fruit\n"..
+			"without leaf together :"},
+		{"image", {1, 1, "nether_shroom_top.png"}},
+		{"image", {1, 1, "nether_fim.png", 3}},
+		{"image", {1, 1, "nether_fruit_no_leaf.png"}},
+		{"image", {1, 1, "nether_shroom_top.png"}},
+		{"y", 0.2},
+		{"text", "Put the result into the furnace\n"..
+			"to cook it into a nether pearl :"},
+		{"image", {1, 1, "nether_pearl.png"}},
+	},
+	{
+		description = "Bricks",
+		{"text", "Craft bricks out of red,\n"..
+			"black and blue netherrack."},
+		{"image", {1, 1, cube("nether_netherrack_brick_black.png"), 1}},
+		{"image", {1, 1, cube("nether_netherrack_brick_blue.png"), 2}},
+		{"image", {1, 1, cube("nether_netherrack_brick.png")}},
+		{"y", 0.4},
+		{"text", "Dig them with at least a level 1 pickaxe."},
+		{"y", 0.2},
+	},
+	{
+		description = "Portals",
+		{"text", "Here you can find out how to built the nether portal."},
+		{"y", 0.3},
+		{"text", "A nether portal requires following nodes:"},
+		{"y", 0.05},
+		{"text", "25 empty nether wooden planks\n"..
+			"16 black netherrack\n"..
+			"12 blue netherrack bricks\n"..
+			"8 red netherrack\n"..
+			"8 cooked nether blood\n"..
+			"4 nether fruits\n"..
+			"2 siwtonic blocks"},
+		{"y", 0.2},
+		{"text", "It should look approximately like this one:"},
+		{"image", {5.625, 6, "nether_teleporter.png", 0, -1.5}},
+		{"y", 5.5},
+		{"text", "Activate it by standing in the middle,\n"..
+			"on the siwtonic block and eating a nether fruit.\n"..
+			"Take enough stuff with you to build a portal when you'll come back."},
+	},
+	{
+		description = "Forests",
+		{"text", "The nether forest is generated in caves,\n"..
+			"above the usual nether."},
+		{"y", 0.2},
+		{"text", "There you can find some plants:"},
+		{"image", {1, 1, "nether_grass_middle.png", 1}},
+		{"image", {1, 1, "nether_grass_big.png", 2}},
+		{"image", {1, 1, "nether_grass_small.png"}},
+		{"y", 0.2},
+		{"text", "Use the nether forest grass to get paper.\n"..
+			"Craft paper out of the dried grass."},
+		{"image", {1, 1, cube("nether_tree_top.png", "nether_tree.png", "nether_tree.png")}},
+		{"y", 0.2},
+		{"text", "Nether trunks can be found at nether trees.\n"..
+			"Craft nether wood out of nether trunk."},
+		{"image", {1, 1, "nether_glowflower.png"}},
+		{"y", 0.2},
+		{"text", "Use it for lighting and decoration."},
+	},
+}
+
+-- the size of guide pages
+local guide_size = {x=40, y=10, cx=0.2, cy=0.2}
+
+-- informations about settings and ...
+local formspec_offset = {x=0.25, y=0.50}
+local font_size
+if minetest.is_singleplayer() then
+	font_size = tonumber(minetest.settings:get("font_size")) or 13
+else
+	font_size = 13
+end
+guide_size.fx = math.floor((40*(guide_size.cx+formspec_offset.x))*font_size)
+guide_size.fy = font_size/40
+
+-- the default guide formspecs
+local guide_forms = {
+	contents = "size[3.6,"..(#guide_infos)-2 ..";]label["..guide_size.cx+0.7 ..","..guide_size.cy+0.2 ..";Contents:]",
+}
+
+-- change the infos to formspecs
+for n,data in ipairs(guide_infos) do
+	local form = ""
+	local y = 0
+	local x = guide_size.cx
+	for _,i in ipairs(data) do
+		local typ, content = unpack(i)
+		if typ == "y" then
+			y = y+content
+		elseif typ == "x" then
+			x = math.max(x, content)
+		elseif typ == "text" then
+			local tab = minetest.wrap_text(content, guide_size.fx, true)
+			local l = guide_size.cx
+			for _,str in ipairs(tab) do
+				form = form.."label["..guide_size.cx ..","..guide_size.cy+y..";"..str.."]"
+				y = y+guide_size.fy
+				l = math.max(l, #str)
+			end
+			x = math.max(x, l/font_size)
+		elseif typ == "image" then
+			local w, h, texture_name, px, py = unpack(content)
+			if not px then
+				form = form.."image["..guide_size.cx..","..guide_size.cy+y+h*0.3 ..";"..w..","..h..";"..texture_name.."]"
+				y = y+h
+			else
+				px = guide_size.cx+px
+				py = py or 0
+				form = form.."image["..px..","..
+					guide_size.cy+y+h*0.3+py ..";"..w..","..h..";"..texture_name.."]"
+				x = math.max(x, px+w)
+			end
+		end
+	end
+	form = "size["..x*1.8 ..","..y+1 ..";]"..form.."button["..x/2-0.5 ..","..y ..";1,2;quit;Back]"
+	guide_forms[n] = {data.description, form}
+end
+
+local desc_tab = {}
+for n,i in ipairs(guide_forms) do
+	desc_tab[i[1]] = n
+end
+
+-- creates contents formspec
+for y,i in ipairs(guide_forms) do
+	local desc = i[1]
+	local s = #desc * 1.3 / font_size + 1.5
+	guide_forms.contents = guide_forms.contents ..
+		"button[" .. guide_size.cx * 12 / s - 0.5 .. "," ..
+		guide_size.cy + y / 1.3 .. ";" .. s .. ",1;name;" .. desc .. "]"
+end
+
+-- shows the contents of the formspec
+local function show_guide(pname)
+	minetest.show_formspec(pname, "nether_guide_contents", guide_forms["contents"])
+end
+
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if formname == "nether_guide_contents" then
+		local fname = fields.name
+		local pname = player:get_player_name()
+		if fname
+		and pname then
+			minetest.show_formspec(pname, "nether_guide", guide_forms[desc_tab[fname]][2])
+		end
+	elseif formname == "nether_guide" then
+		local fname = fields.quit
+		local pname = player:get_player_name()
+		if fname
+		and pname then
+			minetest.show_formspec(pname, "nether_guide_contents", guide_forms["contents"])
+		end
+	end
+end)
+
+minetest.register_chatcommand("nether_help", {
+	params = "",
+	description = "Shows a nether guide",
+	func = function(name)
+		local player = minetest.get_player_by_name(name)
+		if not player then
+			minetest.chat_send_player(name, "Something went wrong.")
+			return false
+		end
+		if player:get_pos().y > nether.start then
+			minetest.chat_send_player(name,
+				"Usually you don't neet this guide here. " ..
+				"You can view it in the nether.")
+			return false
+		end
+		minetest.chat_send_player(name, "Showing guide...")
+		show_guide(name)
+		return true
+	end
+})
diff --git a/nether/nether/init.lua b/nether/nether/init.lua
new file mode 100644
index 00000000..184338ee
--- /dev/null
+++ b/nether/nether/init.lua
@@ -0,0 +1,1046 @@
+-- Nether Mod (based on Nyanland by Jeija, Catapult by XYZ, and Livehouse by neko259)
+-- lkjoel (main developer, code, ideas, textures)
+-- == CONTRIBUTERS ==
+-- jordan4ibanez (code, ideas, textures)
+-- Gilli (code, ideas, textures, mainly for the Glowstone)
+-- Death Dealer (code, ideas, textures)
+-- LolManKuba (ideas, textures)
+-- IPushButton2653 (ideas, textures)
+-- Menche (textures)
+-- sdzen (ideas)
+-- godkiller447 (ideas)
+-- If I didn't list you, please let me know!
+
+local load_time_start = minetest.get_us_time()
+
+if not rawget(_G, "nether") then
+	nether = {}
+end
+
+--== EDITABLE OPTIONS ==--
+
+--says some information.
+nether.info = true
+
+-- tell everyone about the generation
+nether.inform_all = minetest.is_singleplayer()
+
+--1:<a bit of information> 2:<acceptable amount of information> 3:<lots of text>
+nether.max_spam = 2
+
+-- Depth of the nether
+local nether_middle = -20000
+
+-- forest bottom perlin multiplication
+local f_bottom_scale = 4
+
+-- forest bottom height
+local f_h_min = nether_middle+10
+
+-- forest top height
+local f_h_max = f_h_min+250
+
+-- Frequency of trees in the nether forest (higher is less frequent)
+local tree_rarity = 200
+
+-- Frequency of glowflowers in the nether forest (higher is less frequent)
+local glowflower_rarity = 120
+
+-- Frequency of nether grass in the nether forest (higher is less frequent)
+local grass_rarity = 2
+
+-- Frequency of nether mushrooms in the nether forest (higher is less frequent)
+local mushroom_rarity = 80
+
+local abm_tree_interval = 864
+local abm_tree_chance = 100
+
+-- height of the nether generation's end
+nether.start = f_h_max+100
+
+-- Height of the nether (bottom of the nether is nether_middle - NETHER_HEIGHT)
+local NETHER_HEIGHT = 30
+
+-- Maximum amount of randomness in the map generation
+local NETHER_RANDOM = 2
+
+-- Frequency of Glowstone on the "roof" of the Nether (higher is less frequent)
+local GLOWSTONE_FREQ_ROOF = 500
+
+-- Frequency of lava (higher is less frequent)
+local LAVA_FREQ = 100
+
+local nether_structure_freq = 350
+local NETHER_SHROOM_FREQ = 100
+
+-- Maximum height of lava
+--LAVA_HEIGHT = 2
+-- Frequency of Glowstone on lava (higher is less frequent)
+--GLOWSTONE_FREQ_LAVA = 2
+-- Height of nether structures
+--NETHER_TREESIZE = 2
+-- Frequency of apples in a nether structure (higher is less frequent)
+--NETHER_APPLE_FREQ = 5
+-- Frequency of healing apples in a nether structure (higher is less frequent)
+--NETHER_HEAL_APPLE_FREQ = 10
+-- Start position for the Throne of Hades (y is relative to the bottom of the
+-- nether)
+--HADES_THRONE_STARTPOS = {x=0, y=1, z=0}
+-- Spawn pos for when the nether hasn't been loaded yet (i.e. no portal in the
+-- nether) (y is relative to the bottom of the nether)
+--NETHER_SPAWNPOS = {x=0, y=5, z=0}
+-- Structure of the nether portal (all is relative to the nether portal creator
+-- block)
+
+--== END OF EDITABLE OPTIONS ==--
+
+if nether.info then
+	function nether:inform(msg, spam, t)
+		if spam <= self.max_spam then
+			local info
+			if t then
+				info = "[nether] " .. msg .. (" after ca. %.3g s"):format(
+					(minetest.get_us_time() - t) / 1000000)
+			else
+				info = "[nether] " .. msg
+			end
+			print(info)
+			if self.inform_all then
+				minetest.chat_send_all(info)
+			end
+		end
+	end
+else
+	function nether.inform()
+	end
+end
+
+
+local path = minetest.get_modpath"nether"
+local nether_weird_noise = dofile(path.."/weird_mapgen_noise.lua")
+dofile(path.."/items.lua")
+--dofile(path.."/furnace.lua")
+dofile(path.."/pearl.lua")
+
+-- Weierstrass function stuff from https://github.com/slemonide/gen
+local SIZE = 1000
+local ssize = math.ceil(math.abs(SIZE))
+local function do_ws_func(depth, a, x)
+	local n = math.pi * x / (16 * SIZE)
+	local y = 0
+	for k=1,depth do
+		y = y + math.sin(k^a * n) / k^a
+	end
+	return SIZE * y / math.pi
+end
+
+local chunksize = minetest.settings:get"chunksize" or 5
+local ws_lists = {}
+local function get_ws_list(a,x)
+        ws_lists[a] = ws_lists[a] or {}
+        local v = ws_lists[a][x]
+        if v then
+                return v
+        end
+        v = {}
+        for x=x,x + (chunksize*16 - 1) do
+		local y = do_ws_func(ssize, a, x)
+                v[x] = y
+        end
+        ws_lists[a][x] = v
+        return v
+end
+
+
+local function dif(z1, z2)
+	return math.abs(z1-z2)
+end
+
+local function pymg(x1, x2, z1, z2)
+	return math.max(dif(x1, x2), dif(z1, z2))
+end
+
+local function r_area(manip, width, height, pos)
+	local emerged_pos1, emerged_pos2 = manip:read_from_map(
+		{x=pos.x-width, y=pos.y, z=pos.z-width},
+		{x=pos.x+width, y=pos.y+height, z=pos.z+width}
+	)
+	return VoxelArea:new({MinEdge=emerged_pos1, MaxEdge=emerged_pos2})
+end
+
+local function set_vm_data(manip, nodes, pos, t1, name, generated)
+	manip:set_data(nodes)
+	manip:write_to_map(not generated)
+	nether:inform(name.." grew at " .. minetest.pos_to_string(pos),
+		generated and 3 or 2, t1)
+end
+
+-- Generated variables
+local NETHER_BOTTOM = (nether_middle - NETHER_HEIGHT)
+nether.buildings = NETHER_BOTTOM+12
+--~ local NETHER_ROOF_ABS = (nether_middle - NETHER_RANDOM)
+local f_yscale_top = (f_h_max-f_h_min)/2
+local f_yscale_bottom = f_yscale_top/2
+--HADES_THRONE_STARTPOS_ABS = {x=HADES_THRONE_STARTPOS.x, y=(NETHER_BOTTOM +
+--HADES_THRONE_STARTPOS.y), z=HADES_THRONE_STARTPOS.z}
+--LAVA_Y = (NETHER_BOTTOM + LAVA_HEIGHT)
+--HADES_THRONE_ABS = {}
+--HADES_THRONE_ENDPOS_ABS = {}
+--HADES_THRONE_GENERATED = minetest.get_worldpath() .. "/netherhadesthrone.txt"
+--NETHER_SPAWNPOS_ABS = {x=NETHER_SPAWNPOS.x, y=(NETHER_BOTTOM +
+--NETHER_SPAWNPOS.y), z=NETHER_SPAWNPOS.z}
+--[[for i,v in ipairs(HADES_THRONE) do
+	v.pos.x = v.pos.x + HADES_THRONE_STARTPOS_ABS.x
+	v.pos.y = v.pos.y + HADES_THRONE_STARTPOS_ABS.y
+	v.pos.z = v.pos.z + HADES_THRONE_STARTPOS_ABS.z
+	HADES_THRONE_ABS[i] = v
+end
+local htx = 0
+local hty = 0
+local htz = 0
+for i,v in ipairs(HADES_THRONE_ABS) do
+	if v.pos.x > htx then
+		htx = v.pos.x
+	end
+	if v.pos.y > hty then
+		hty = v.pos.y
+	end
+	if v.pos.z > htz then
+		htz = v.pos.z
+	end
+end
+HADES_THRONE_ENDPOS_ABS = {x=htx, y=hty, z=htz}]]
+
+local c, nether_tree_nodes
+local function define_contents()
+	c = {
+		ignore = minetest.get_content_id("ignore"),
+		air = minetest.get_content_id("air"),
+		lava = minetest.get_content_id("default:lava_source"),
+		gravel = minetest.get_content_id("default:gravel"),
+		coal = minetest.get_content_id("default:stone_with_coal"),
+		diamond = minetest.get_content_id("default:stone_with_diamond"),
+		mese = minetest.get_content_id("default:mese"),
+
+		--https://github.com/Zeg9/minetest-glow
+		glowstone = minetest.get_content_id("glow:stone"),
+
+		nether_shroom = minetest.get_content_id("riesenpilz:nether_shroom"),
+
+		netherrack = minetest.get_content_id("nether:netherrack"),
+		netherrack_tiled = minetest.get_content_id("nether:netherrack_tiled"),
+		netherrack_black = minetest.get_content_id("nether:netherrack_black"),
+		netherrack_blue = minetest.get_content_id("nether:netherrack_blue"),
+		netherrack_brick = minetest.get_content_id("nether:netherrack_brick"),
+		white = minetest.get_content_id("nether:white"),
+
+		nether_vine = minetest.get_content_id("nether:vine"),
+		blood = minetest.get_content_id("nether:blood"),
+		blood_top = minetest.get_content_id("nether:blood_top"),
+		blood_stem = minetest.get_content_id("nether:blood_stem"),
+		nether_apple = minetest.get_content_id("nether:apple"),
+
+		nether_tree = minetest.get_content_id("nether:tree"),
+		nether_tree_corner = minetest.get_content_id("nether:tree_corner"),
+		nether_leaves = minetest.get_content_id("nether:leaves"),
+		nether_grass = {
+			minetest.get_content_id("nether:grass_small"),
+			minetest.get_content_id("nether:grass_middle"),
+			minetest.get_content_id("nether:grass_big")
+		},
+		glowflower = minetest.get_content_id("nether:glowflower"),
+		nether_dirt = minetest.get_content_id("nether:dirt"),
+		nether_dirt_top = minetest.get_content_id("nether:dirt_top"),
+		nether_dirt_bottom = minetest.get_content_id("nether:dirt_bottom"),
+	}
+	local trn = {c.nether_tree, c.nether_tree_corner, c.nether_leaves,
+		c.nether_fruit}
+	nether_tree_nodes = {}
+	for i = 1,#trn do
+		nether_tree_nodes[trn[i]] = true
+	end
+end
+
+local pr, contents_defined
+
+local function return_nether_ore(id, glowstone)
+	if glowstone
+	and pr:next(0,GLOWSTONE_FREQ_ROOF) == 1 then
+		return c.glowstone
+	end
+	if id == c.coal then
+		return c.netherrack_tiled
+	end
+	if id == c.gravel then
+		return c.netherrack_black
+	end
+	if id == c.diamond then
+		return c.netherrack_blue
+	end
+	if id == c.mese then
+		return c.white
+	end
+	return c.netherrack
+end
+
+local f_perlins = {}
+
+-- abs(v) < 1-(persistance^octaves))/(1-persistance) = amp
+--local perlin1 = minetest.get_perlin(13,3, 0.5, 50) --Get map specific perlin
+--	local perlin2 = minetest.get_perlin(133,3, 0.5, 10)
+--	local perlin3 = minetest.get_perlin(112,3, 0.5, 5)
+local tmp = f_yscale_top*4
+local tmp2 = tmp/f_bottom_scale
+local perlins = {
+	{ -- amp 1.75
+		seed = 13,
+		octaves = 3,
+		persist = 0.5,
+		spread = {x=50, y=50, z=50},
+		scale = 1,
+		offset = 0,
+	},
+	{-- amp 1.75
+		seed = 133,
+		octaves = 3,
+		persist = 0.5,
+		spread = {x=10, y=10, z=10},
+		scale = 1,
+		offset = 0,
+	},
+	{-- amp 1.75
+		seed = 112,
+		octaves = 3,
+		persist = 0.5,
+		spread = {x=5, y=5, z=5},
+		scale = 1,
+		offset = 0,
+	},
+	--[[forest_bottom = {
+		seed = 11,
+		octaves = 3,
+		persist = 0.8,
+		spread = {x=tmp2, y=tmp2, z=tmp2},
+		scale = 1,
+		offset = 0,
+	},]]
+	forest_top = {-- amp 2.44
+		seed = 21,
+		octaves = 3,
+		persist = 0.8,
+		spread = {x=tmp, y=tmp, z=tmp},
+		scale = 1,
+		offset = 0,
+	},
+}
+
+-- buffers, see https://forum.minetest.net/viewtopic.php?f=18&t=16043
+local pelin_maps
+local pmap1 = {}
+local pmap2 = {}
+local pmap3 = {}
+local pmap_f_top = {}
+local data = {}
+
+local structures_enabled = true
+local vine_maxlength = math.floor(NETHER_HEIGHT/4+0.5)
+-- Create the Nether
+minetest.register_on_generated(function(minp, maxp, seed)
+	--avoid big map generation
+	if not (maxp.y >= NETHER_BOTTOM-100 and minp.y <= nether.start) then
+		return
+	end
+
+	local t1 = minetest.get_us_time()
+	nether:inform("generates at: x=["..minp.x.."; "..maxp.x.."]; y=[" ..
+		minp.y.."; "..maxp.y.."]; z=["..minp.z.."; "..maxp.z.."]", 2)
+
+	if not contents_defined then
+		define_contents()
+		contents_defined = true
+	end
+
+	local buildings = 0
+	if maxp.y <= NETHER_BOTTOM then
+		buildings = 1
+	elseif minp.y <= nether.buildings then
+		buildings = 2
+	end
+
+	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+	vm:get_data(data)
+	local area = VoxelArea:new{MinEdge=emin, MaxEdge=emax}
+
+	pr = PseudoRandom(seed+33)
+	local tab,num = {},1
+	local trees,num_trees = {},1
+
+	--local perlin1 = minetest.get_perlin(13,3, 0.5, 50)
+	--local perlin2 = minetest.get_perlin(133,3, 0.5, 10)
+	--local perlin3 = minetest.get_perlin(112,3, 0.5, 5)
+
+	local side_length = maxp.x - minp.x + 1
+	local map_lengths_xyz = {x=side_length, y=side_length, z=side_length}
+
+	if not pelin_maps then
+		pelin_maps = {
+			a = minetest.get_perlin_map(perlins[1], map_lengths_xyz),
+			b = minetest.get_perlin_map(perlins[2], map_lengths_xyz),
+			c = minetest.get_perlin_map(perlins[3], map_lengths_xyz),
+			forest_top = minetest.get_perlin_map(perlins.forest_top,
+				map_lengths_xyz),
+		}
+	end
+	pelin_maps.a:get_2d_map_flat({x=minp.x, y=minp.z}, pmap1)
+	pelin_maps.b:get_2d_map_flat({x=minp.x, y=minp.z}, pmap2)
+	pelin_maps.c:get_2d_map_flat({x=minp.x, y=minp.z}, pmap3)
+
+	local forest_possible = maxp.y > f_h_min and minp.y < f_h_max
+
+	--local pmap_f_bottom = minetest.get_perlin_map(perlins.forest_bottom,
+	-- map_lengths_xyz):get_2d_map_flat({x=minp.x, y=minp.z})
+	local perlin_f_bottom, strassx, strassz
+	if forest_possible then
+		perlin_f_bottom = minetest.get_perlin(11, 3, 0.8, tmp2)
+		pelin_maps.forest_top:get_2d_map_flat({x=minp.x, y=minp.z}, pmap_f_top)
+		strassx = get_ws_list(2, minp.x)
+		strassz = get_ws_list(2, minp.z)
+	end
+
+	local num2, tab2
+	if buildings >= 1 then
+		num2 = 1
+		tab2 = nether_weird_noise({x=minp.x, y=nether.buildings-79, z=minp.z},
+			pymg, 200, 8, 10, side_length-1)
+	end
+
+	local count = 0
+	for z=minp.z, maxp.z do
+		for x=minp.x, maxp.x do
+
+			count = count+1
+
+			local test = pmap1[count]+1
+			local test2 = pmap2[count]
+			local test3 = math.abs(pmap3[count])
+
+			local t = math.floor(test*3+0.5)
+
+			local h
+			if test2 < 0 then
+				h = math.floor(test2*3+0.5)-1
+			else
+				h = 3+t+pr:next(0,NETHER_RANDOM)
+			end
+
+			local generate_vine = false
+			if test3 >= 0.72+pr:next(0,NETHER_RANDOM)/10
+			and pr:next(0,NETHER_RANDOM) == 1 then
+				generate_vine = true
+			end
+
+			local bottom = NETHER_BOTTOM+h
+			local top = nether_middle-pr:next(0,NETHER_RANDOM)+t
+
+			local py_h = 0
+			local difn, noisp, py_h_g
+			if buildings >= 1 then
+				py_h = tab2[num2].y
+				num2 = num2+1
+
+				difn = nether.buildings-py_h
+				if difn == 5 then
+					noisp = 1
+				elseif difn < 5 then
+					noisp = 2
+				end
+				py_h_g = nether.buildings-7
+			end
+
+			local vi = area:index(x, minp.y, z)
+			if buildings == 1
+			and noisp then
+				if noisp == 1 then
+					for _ = 1,side_length do
+						data[vi] = c.netherrack_brick
+						vi = vi + area.ystride
+					end
+				else
+					for _ = 1,side_length do
+						data[vi] = c.lava
+						vi = vi + area.ystride
+					end
+				end
+			else
+
+				local r_structure = pr:next(1,nether_structure_freq)
+				local r_shroom = pr:next(1,NETHER_SHROOM_FREQ)
+				local r_glowstone = pr:next(0,GLOWSTONE_FREQ_ROOF)
+				local r_vine_length = pr:next(1,vine_maxlength)
+
+				local f_bottom, f_top, is_forest, f_h_dirt
+				if forest_possible then
+					local p = {x=math.floor(x/f_bottom_scale),
+						z=math.floor(z/f_bottom_scale)}
+					local pstr = p.x.." "..p.z
+					if not f_perlins[pstr] then
+						f_perlins[pstr] = math.floor(f_h_min + (math.abs(
+							perlin_f_bottom:get_2d{x=p.x, y=p.z} + 1))
+							* f_yscale_bottom + 0.5)
+					end
+					local top_noise = pmap_f_top[count]+1
+					if top_noise < 0 then
+						top_noise = -top_noise/10
+						--nether:inform("ERROR: (perlin noise) "..
+						-- pmap_f_top[count].." is not inside [-1; 1]", 1)
+					end
+					f_top = math.floor(f_h_max - top_noise*f_yscale_top + 0.5)
+					f_bottom = f_perlins[pstr]+pr:next(0,f_bottom_scale-1)
+					is_forest = f_bottom < f_top
+					f_h_dirt = f_bottom-pr:next(0,1)
+				end
+
+				for y=minp.y, maxp.y do
+					local d_p_addp = data[vi]
+					--if py_h >= maxp.y-4 then
+					if y <= py_h
+					and noisp then
+						if noisp == 1 then
+							data[vi] = c.netherrack_brick
+						elseif noisp == 2 then
+							if y == py_h then
+								data[vi] = c.netherrack_brick
+							elseif y == py_h_g
+							and pr:next(1,3) <= 2 then
+								data[vi] = c.netherrack
+							elseif y <= py_h_g then
+								data[vi] = c.lava
+							else
+								data[vi] = c.air
+							end
+						end
+					elseif d_p_addp ~= c.air then
+
+						if is_forest
+						and y == f_bottom then
+							data[vi] = c.nether_dirt_top
+						elseif is_forest
+						and y < f_bottom
+						and y >= f_h_dirt then
+							data[vi] = c.nether_dirt
+						elseif is_forest
+						and y == f_h_dirt-1 then
+							data[vi] = c.nether_dirt_bottom
+						elseif is_forest
+						and y == f_h_dirt+1 then
+							if pr:next(1,tree_rarity) == 1 then
+								trees[num_trees] = {x=x, y=y, z=z}
+								num_trees = num_trees+1
+							elseif pr:next(1,mushroom_rarity) == 1 then
+								data[vi] = c.nether_shroom
+							elseif pr:next(1,glowflower_rarity) == 1 then
+								data[vi] = c.glowflower
+							elseif pr:next(1,grass_rarity) == 1 then
+								data[vi] = c.nether_grass[pr:next(1,3)]
+							else
+								data[vi] = c.air
+							end
+						elseif is_forest
+						and y > f_bottom
+						and y < f_top then
+							if not nether_tree_nodes[d_p_addp] then
+								data[vi] = c.air
+							end
+						elseif is_forest
+						and y == f_top then
+							local sel = math.floor(strassx[x]+strassz[z]+0.5)%10
+							if sel <= 5 then
+								data[vi] = return_nether_ore(d_p_addp, true)
+							elseif sel == 6 then
+								data[vi] = c.netherrack_black
+							elseif sel == 7 then
+								data[vi] = c.glowstone
+							else
+								data[vi] = c.air
+							end
+
+						elseif y <= NETHER_BOTTOM then
+							if y <= bottom then
+								data[vi] = return_nether_ore(d_p_addp, true)
+							else
+								data[vi] = c.lava
+							end
+						elseif r_structure == 1
+						and y == bottom then
+							tab[num] = {x=x, y=y-1, z=z}
+							num = num+1
+						elseif y <= bottom then
+							if pr:next(1,LAVA_FREQ) == 1 then
+								data[vi] = c.lava
+							else
+								data[vi] = return_nether_ore(d_p_addp, false)
+							end
+						elseif r_shroom == 1
+						and r_structure ~= 1
+						and y == bottom+1 then
+							data[vi] = c.nether_shroom
+						elseif (y == top and r_glowstone == 1) then
+							data[vi] = c.glowstone
+						elseif y >= top then
+							data[vi] = return_nether_ore(d_p_addp, true)
+						elseif y <= top-1
+						and generate_vine
+						and y >= top-r_vine_length then
+							data[vi] = c.nether_vine
+						else
+							data[vi] = c.air
+						end
+					end
+					vi = vi + area.ystride
+				end
+			end
+		end
+	end
+	vm:set_data(data)
+--	vm:set_lighting(12)
+--	vm:calc_lighting()
+--	vm:update_liquids()
+	vm:write_to_map(false)
+
+	nether:inform("nodes set", 2, t1)
+
+	local t2 = minetest.get_us_time()
+	local tr_bl_cnt = 0
+
+	if structures_enabled then -- Blood netherstructures
+		tr_bl_cnt = #tab
+		for i = 1,tr_bl_cnt do
+			nether.grow_netherstructure(tab[i], true)
+		end
+	end
+
+	if forest_possible then -- Forest trees
+		tr_bl_cnt = tr_bl_cnt + #trees
+		for i = 1,#trees do
+			nether.grow_tree(trees[i], true)
+		end
+	end
+
+	if tr_bl_cnt > 0 then
+		nether:inform(tr_bl_cnt .. " trees and blood structures set", 2, t2)
+	end
+
+	t2 = minetest.get_us_time()
+	minetest.fix_light(minp, maxp)
+
+	nether:inform("light fixed", 2, t2)
+
+	nether:inform("done", 1, t1)
+end)
+
+
+function nether.grow_netherstructure(pos, generated)
+	local t1 = minetest.get_us_time()
+
+	if not contents_defined then
+		define_contents()
+		contents_defined = true
+	end
+
+	if not pos.x then print(dump(pos))
+		nether:inform("Error: "..dump(pos), 1)
+		return
+	end
+
+	local height = 6
+	local manip = minetest.get_voxel_manip()
+	local area = r_area(manip, 2, height, pos)
+	local nodes = manip:get_data()
+
+	local vi = area:indexp(pos)
+	for _ = 0, height-1 do
+		nodes[vi] = c.blood_stem
+		vi = vi + area.ystride
+	end
+
+	for i = -1,1 do
+		for j = -1,1 do
+			nodes[area:index(pos.x+i, pos.y+height, pos.z+j)] = c.blood_top
+		end
+	end
+
+	for k = -1, 1, 2 do
+		for l = -2+1, 2 do
+			local p1 = {pos.x+2*k, pos.y+height, pos.z-l*k}
+			local p2 = {pos.x+l*k, pos.y+height, pos.z+2*k}
+			local udat = c.blood_top
+			if math.random(2) == 1 then
+				nodes[area:index(p1[1], p1[2], p1[3])] = c.blood_top
+				nodes[area:index(p2[1], p2[2], p2[3])] = c.blood_top
+				udat = c.blood
+			end
+			nodes[area:index(p1[1], p1[2]-1, p1[3])] = udat
+			nodes[area:index(p2[1], p2[2]-1, p2[3])] = udat
+		end
+		for l = 0, 1 do
+			for _,p in ipairs({
+				{pos.x+k, pos.y+height-1, pos.z-l*k},
+				{pos.x+l*k, pos.y+height-1, pos.z+k},
+			}) do
+				if math.random(2) == 1 then
+					nodes[area:index(p[1], p[2], p[3])] = c.nether_apple
+				--elseif math.random(10) == 1 then
+				--	nodes[area:index(p[1], p[2], p[3])] = c.apple
+				end
+			end
+		end
+	end
+	set_vm_data(manip, nodes, pos, t1, "blood", generated)
+end
+
+
+local poshash = minetest.hash_node_position
+local pos_from_hash = minetest.get_position_from_hash
+
+local function soft_node(id)
+	return id == c.air or id == c.ignore
+end
+
+local function update_minmax(min, max, p)
+	min.x = math.min(min.x, p.x)
+	max.x = math.max(max.x, p.x)
+	min.z = math.min(min.z, p.z)
+	max.z = math.max(max.z, p.z)
+end
+
+local fruit_chances = {}
+for y = -2,1 do --like a hyperbola
+	fruit_chances[y] = math.floor(-4/(y-2)+0.5)
+end
+
+local dirs = {
+	{-1, 0, 12, 19},
+	{1, 0, 12, 13},
+	{0, 1, 4},
+	{0, -1, 4, 10},
+}
+
+local h_max = 26
+local h_stem_min = 3
+local h_stem_max = 7
+local h_arm_min = 2
+local h_arm_max = 6
+local r_arm_min = 1
+local r_arm_max = 5
+local fruit_rarity = 25 --a bigger number results in less fruits
+local leaf_thickness = 3 --a bigger number results in more blank trees
+
+local h_trunk_max = h_max-h_arm_max
+
+function nether.grow_tree(pos, generated)
+	local t1 = minetest.get_us_time()
+
+	if not contents_defined then
+		define_contents()
+		contents_defined = true
+	end
+
+	local min = vector.new(pos)
+	local max = vector.new(pos)
+	min.y = min.y-1
+	max.y = max.y+h_max
+
+	local trunks = {}
+	local trunk_corners = {}
+	local h_stem = math.random(h_stem_min, h_stem_max)
+	local todo,n = {{x=pos.x, y=pos.y+h_stem, z=pos.z}},1
+	while n do
+		local p = todo[n]
+		todo[n] = nil
+		n = next(todo)
+
+		local used_dirs,u = {},1
+		for _,dir in pairs(dirs) do
+			if math.random(1,2) == 1 then
+				used_dirs[u] = dir
+				u = u+1
+			end
+		end
+		if not used_dirs[1] then
+			local dir1 = math.random(4)
+			local dir2 = math.random(3)
+			if dir1 <= dir2 then
+				dir2 = dir2+1
+			end
+			used_dirs[1] = dirs[dir1]
+			used_dirs[2] = dirs[dir2]
+		end
+		for _,dir in pairs(used_dirs) do
+			local p = vector.new(p)
+			local r = math.random(r_arm_min, r_arm_max)
+			for j = 1,r do
+				local x = p.x+j*dir[1]
+				local z = p.z+j*dir[2]
+				trunks[poshash{x=x, y=p.y, z=z}] = dir[3]
+			end
+			r = r+1
+			p.x = p.x+r*dir[1]
+			p.z = p.z+r*dir[2]
+			trunk_corners[poshash(p)] = dir[4] or dir[3]
+			local h = math.random(h_arm_min, h_arm_max)
+			for i = 1,h do
+				p.y = p.y + i
+				trunks[poshash(p)] = true
+				p.y = p.y - i
+			end
+			p.y = p.y+h
+			--n = #todo+1 -- caused small trees
+			todo[#todo+1] = p
+		end
+		if p.y > pos.y+h_trunk_max then
+			break
+		end
+
+		n = n or next(todo)
+	end
+	local leaves = {}
+	local fruits = {}
+	local trunk_ps = {}
+	local count = 0
+
+	local ps = {}
+	local trunk_count = 0
+	for i,par2 in pairs(trunks) do
+		local pos = pos_from_hash(i)
+		update_minmax(min, max, pos)
+		local z,y,x = pos.z, pos.y, pos.x
+		trunk_count = trunk_count+1
+		ps[trunk_count] = {z,y,x, par2}
+	end
+
+	for _,d in pairs(ps) do
+		if d[4] == true then
+			d[4] = nil
+		end
+		trunk_ps[#trunk_ps+1] = d
+		local pz, py, px = unpack(d)
+		count = count+1
+		if count > leaf_thickness then
+			count = 0
+			for y = -2,2 do
+				local fruit_chance = fruit_chances[y]
+				for z = -2,2 do
+					for x = -2,2 do
+						local distq = x*x+y*y+z*z
+						if distq ~= 0
+						and math.random(1, math.sqrt(distq)) == 1 then
+							local x = x+px
+							local y = y+py
+							local z = z+pz
+							local vi = poshash{x=x, y=y, z=z}
+							if not trunks[vi] then
+								if fruit_chance
+								and math.random(1, fruit_rarity) == 1
+								and math.random(1, fruit_chance) == 1 then
+									fruits[vi] = true
+								else
+									leaves[vi] = true
+								end
+								update_minmax(min, max, {x=x, z=z})
+							end
+						end
+					end
+				end
+			end
+		end
+	end
+
+	--ps = nil
+	--collectgarbage()
+
+	for i = -1,h_stem+1 do
+		-- param2 explicitly set 0 due to possibly previous leaves node
+		trunk_ps[#trunk_ps+1] = {pos.z, pos.y+i, pos.x, 0}
+	end
+
+	local manip = minetest.get_voxel_manip()
+	local emerged_pos1, emerged_pos2 = manip:read_from_map(min, max)
+	local area = VoxelArea:new({MinEdge=emerged_pos1, MaxEdge=emerged_pos2})
+	local nodes = manip:get_data()
+	local param2s = manip:get_param2_data()
+
+	for i in pairs(leaves) do
+		local p = area:indexp(pos_from_hash(i))
+		if soft_node(nodes[p]) then
+			nodes[p] = c.nether_leaves
+			param2s[p] = math.random(0,179)
+			--param2s[p] = math.random(0,44)
+		end
+	end
+
+	for i in pairs(fruits) do
+		local p = area:indexp(pos_from_hash(i))
+		if soft_node(nodes[p]) then
+			nodes[p] = c.nether_apple
+		end
+	end
+
+	for i = 1,#trunk_ps do
+		local p = trunk_ps[i]
+		local par = p[4]
+		p = area:index(p[3], p[2], p[1])
+		if par then
+			param2s[p] = par
+		end
+		nodes[p] = c.nether_tree
+	end
+
+	for i,par2 in pairs(trunk_corners) do
+		local vi = area:indexp(pos_from_hash(i))
+		nodes[vi] = c.nether_tree_corner
+		param2s[vi] = par2
+	end
+
+	manip:set_data(nodes)
+	manip:set_param2_data(param2s)
+	manip:write_to_map(not generated)
+	nether:inform("a nether tree with " .. trunk_count ..
+		" branch trunk nodes grew at " .. minetest.pos_to_string(pos),
+		generated and 3 or 2, t1)
+end
+
+
+--abms
+
+minetest.register_abm({
+	nodenames = {"nether:sapling"},
+	neighbors = {"nether:blood_top"},
+	interval = 20,
+	chance = 8,
+	action = function(pos)
+		local under = {x=pos.x, y=pos.y-1, z=pos.z}
+		if minetest.get_node_light(pos) < 4
+		and minetest.get_node({x=pos.x, y=pos.y+1, z=pos.z}).name == "air"
+		and minetest.get_node(under).name == "nether:blood_top" then
+			nether.grow_netherstructure(under)
+		end
+	end
+})
+
+minetest.register_abm({
+	nodenames = {"nether:tree_sapling"},
+	neighbors = {"group:nether_dirt"},
+	interval = abm_tree_interval,
+	chance = abm_tree_chance,
+	action = function(pos)
+		if minetest.get_node({x=pos.x, y=pos.y+2, z=pos.z}).name == "air"
+		and minetest.get_node({x=pos.x, y=pos.y+1, z=pos.z}).name == "air" then
+			local udata = minetest.registered_nodes[
+				minetest.get_node{x=pos.x, y=pos.y-1, z=pos.z}.name]
+			if udata
+			and udata.groups
+			and udata.groups.nether_dirt then
+				nether.grow_tree(pos)
+			end
+		end
+	end
+})
+
+minetest.register_abm({
+	nodenames = {"nether:netherrack_soil"},
+	neighbors = {"air"},
+	interval = 20,
+	chance = 20,
+	action = function(pos, node)
+		local par2 = node.param2
+		if par2 == 0 then
+			return
+		end
+		pos.y = pos.y+1
+		--mushrooms grow at dark places
+		if (minetest.get_node_light(pos) or 16) > 7 then
+			return
+		end
+		if minetest.get_node(pos).name == "air" then
+			minetest.set_node(pos, {name="riesenpilz:nether_shroom"})
+			pos.y = pos.y-1
+			minetest.set_node(pos,
+				{name="nether:netherrack_soil", param2=par2-1})
+		end
+	end
+})
+
+local function grass_allowed(pos)
+	local nd = minetest.get_node(pos).name
+	if nd == "air" then
+		return true
+	end
+	if nd == "ignore" then
+		return 0
+	end
+	local data = minetest.registered_nodes[nd]
+	if not data then
+		-- unknown node
+		return false
+	end
+	local drawtype = data.drawtype
+	if drawtype
+	and drawtype ~= "normal"
+	and drawtype ~= "liquid"
+	and drawtype ~= "flowingliquid" then
+		return true
+	end
+	local light = data.light_source
+	if light
+	and light > 0 then
+		return true
+	end
+	return false
+end
+
+minetest.register_abm({
+	nodenames = {"nether:dirt"},
+	interval = 20,
+	chance = 9,
+	action = function(pos)
+		local allowed = grass_allowed({x=pos.x, y=pos.y+1, z=pos.z})
+		if allowed == 0 then
+			return
+		end
+		if allowed then
+			minetest.set_node(pos, {name="nether:dirt_top"})
+		end
+	end
+})
+
+minetest.register_abm({
+	nodenames = {"nether:dirt_top"},
+	interval = 30,
+	chance = 9,
+	action = function(pos)
+		local allowed = grass_allowed({x=pos.x, y=pos.y+1, z=pos.z})
+		if allowed == 0 then
+			return
+		end
+		if not allowed then
+			minetest.set_node(pos, {name="nether:dirt"})
+		end
+	end
+})
+
+
+minetest.register_privilege("nether",
+	"Allows sending players to nether and extracting them")
+
+dofile(path.."/crafting.lua")
+dofile(path.."/portal.lua")
+dofile(path.."/guide.lua")
+
+
+local time = (minetest.get_us_time() - load_time_start) / 1000000
+local msg = ("[nether] loaded after ca. %g seconds."):format(time)
+if time > 0.01 then
+	print(msg)
+else
+	minetest.log("info", msg)
+end
diff --git a/nether/nether/items.lua b/nether/nether/items.lua
new file mode 100644
index 00000000..1e3b28c9
--- /dev/null
+++ b/nether/nether/items.lua
@@ -0,0 +1,1030 @@
+local nether_sound = default.node_sound_stone_defaults({
+	dig = {name="nether_dig", gain=0.7},
+	dug = {name="nether_dug", gain=1},
+	footstep = {name="nether_footstep", gain=0.4}
+})
+
+local add_fence = minetest.register_fence
+local function add_more_nodes(name)
+	local nd = "nether:"..name
+	if not string.find(name, "nether") then
+		name = "nether_"..name
+	end
+	local data = minetest.registered_nodes[nd]
+	stairs.register_stair_and_slab(name, nd,
+		data.groups,
+		data.tiles,
+		data.description.." Stair",
+		data.description.." Slab",
+		data.sounds
+	)
+	if add_fence then
+		add_fence({fence_of = nd})
+	end
+end
+
+--[[
+local function add_fence(name)
+	local def = minetest.registered_nodes[name]
+	local fencedef = {}
+	for _,i in pairs({"walkable", "sunlike_propagates"}) do
+		if def[i] ~= nil then
+			fencedef[i] = def[i]
+		end
+	end
+end
+--]]
+
+local creative_installed = minetest.global_exists("creative")
+
+local function digging_allowed(player, v)
+	if not player then
+		return false
+	end
+	if creative_installed
+	and creative.is_enabled_for(player:get_player_name()) then
+		return true
+	end
+	local tool = player:get_wielded_item():get_name()
+	tool = minetest.registered_tools[tool] or tool == ""
+		and minetest.registered_items[tool]
+	if not tool
+	or not tool.tool_capabilities then
+		return false
+	end
+	local groups = tool.tool_capabilities.groupcaps
+	if not groups then
+		return false
+	end
+	if groups.nether
+	and groups.nether.times[v] then
+		return true
+	end
+	return false
+end
+
+-- Netherrack
+minetest.register_node("nether:netherrack", {
+	description = "Netherrack",
+	tiles = {"nether_netherrack.png"},
+	groups = {nether=2},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 2)
+	end,
+})
+add_more_nodes("netherrack")
+
+minetest.register_node("nether:netherrack_tiled", {
+	description = "Tiled Netherrack",
+	tiles = {"nether_netherrack_tiled.png"},
+	groups = {nether=2},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 2)
+	end,
+})
+add_more_nodes("netherrack_tiled")
+
+minetest.register_node("nether:netherrack_soil", {
+	description = "Dirty Netherrack",
+	tiles = {"nether_netherrack.png^nether_netherrack_soil.png"},
+	groups = {nether=2},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 2)
+	end,
+})
+
+minetest.register_node("nether:netherrack_black", {
+	description = "Black Netherrack",
+	tiles = {"nether_netherrack_black.png"},
+	groups = {nether=2},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 2)
+	end,
+})
+add_more_nodes("netherrack_black")
+
+minetest.register_node("nether:netherrack_blue", {
+	description = "Blue Netherrack",
+	tiles = {"nether_netherrack_blue.png"},
+	groups = {nether=1},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 1)
+	end,
+})
+add_more_nodes("netherrack_blue")
+
+-- Netherbrick
+minetest.register_node("nether:netherrack_brick", {
+	description = "Netherrack Brick",
+	tiles = {"nether_netherrack_brick.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("netherrack_brick")
+
+minetest.register_node("nether:netherrack_brick_blue", {
+	description = "Blue Netherrack Brick",
+	tiles = {"nether_netherrack_brick_blue.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("netherrack_brick_blue")
+
+minetest.register_node("nether:netherrack_brick_black", {
+	description = "Black Netherrack Brick",
+	tiles = {"nether_netherrack_brick_black.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("netherrack_brick_black")
+
+minetest.register_node("nether:white", {
+	description = "Siwtonic block",
+	tiles = {"nether_white.png"},
+	groups = {nether=1},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 1)
+	end,
+})
+add_more_nodes("white")
+
+
+-- Nether blood
+minetest.register_node("nether:sapling", {
+	description = "Nether Blood Child",
+	drawtype = "plantlike",
+	tiles = {"nether_sapling.png"},
+	inventory_image = "nether_sapling.png",
+	wield_image = "nether_sapling.png",
+	paramtype = "light",
+	walkable = false,
+	selection_box = {
+		type = "fixed",
+		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
+	},
+	groups = {snappy=2, oddly_breakable_by_hand=2, attached_node=1},
+	sounds = default.node_sound_leaves_defaults(),
+})
+
+minetest.register_node("nether:blood", {
+	description = "Nether Blood",
+	tiles = {"nether_blood.png"},
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("blood")
+
+minetest.register_node("nether:blood_cooked", {
+	description = "Cooked Nether Blood",
+	tiles = {"nether_blood_cooked.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	furnace_burntime = 10,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("blood_cooked")
+
+minetest.register_node("nether:blood_empty", {
+	description = "Nether Blood Extracted",
+	tiles = {"nether_blood_empty.png"},
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("blood_empty")
+
+
+minetest.register_node("nether:blood_top", {
+	description = "Nether Blood Head",
+	tiles = {"nether_blood_top.png", "nether_blood.png",
+		"nether_blood.png^nether_blood_side.png"},
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("blood_top")
+
+minetest.register_node("nether:blood_top_cooked", {
+	description = "Cooked Nether Blood Head",
+	tiles = {"nether_blood_top_cooked.png", "nether_blood_cooked.png",
+		"nether_blood_cooked.png^nether_blood_side_cooked.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	furnace_burntime = 10,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("blood_top_cooked")
+
+minetest.register_node("nether:blood_top_empty", {
+	description = "Nether Blood Head Extracted",
+	tiles = {"nether_blood_top_empty.png", "nether_blood_empty.png",
+		"nether_blood_empty.png^nether_blood_side_empty.png"},
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("blood_top_empty")
+
+
+minetest.register_node("nether:blood_stem", {
+	description = "Nether Blood Stem",
+	tiles = {"nether_blood_stem_top.png", "nether_blood_stem_top.png",
+		"nether_blood_stem.png"},
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("blood_stem")
+
+minetest.register_node("nether:blood_stem_cooked", {
+	description = "Cooked Nether Blood Stem",
+	tiles = {"nether_blood_stem_top_cooked.png",
+		"nether_blood_stem_top_cooked.png", "nether_blood_stem_cooked.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	furnace_burntime = 30,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("blood_stem_cooked")
+
+minetest.register_node("nether:blood_stem_empty", {
+	description = "Nether Blood Stem Extracted",
+	tiles = {"nether_blood_stem_top_empty.png",
+		"nether_blood_stem_top_empty.png", "nether_blood_stem_empty.png"},
+	groups = {tree=1, choppy=2, oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("blood_stem_empty")
+
+
+minetest.register_node("nether:wood", {
+	description = "Nether Blood Wood",
+	tiles = {"nether_wood.png"},
+	groups = {choppy=2, oddly_breakable_by_hand=2},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("wood")
+
+minetest.register_node("nether:wood_cooked", {
+	description = "Cooked Nether Blood Wood",
+	tiles = {"nether_wood_cooked.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	furnace_burntime = 8,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+add_more_nodes("wood_cooked")
+
+minetest.register_node("nether:wood_empty", {
+	description = "Nether Wood",
+	tiles = {"nether_wood_empty.png"},
+	groups = {choppy=2, oddly_breakable_by_hand=2, wood=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("wood_empty")
+
+minetest.register_node("nether:extractor", {
+	description = "Nether Blood Extractor",
+	tiles = {"nether_blood_extractor.png"},
+	groups = {nether=3},
+	sounds = nether_sound,
+	can_dig = function(_, player)
+		return digging_allowed(player, 3)
+	end,
+})
+
+-- Nether fruit
+minetest.register_node("nether:fruit_leaves", {
+	description = "Nether Fruit Leaves",
+	tiles = {"nether_fruit_leaves.png"},
+	groups = {fleshy=3, dig_immediate=2},
+	sounds = default.node_sound_defaults(),
+	furnace_burntime = 18,
+})
+add_more_nodes("fruit_leaves")
+
+local function room_for_items(inv)
+	local free_slots = 0
+	for _,i in ipairs(inv:get_list("main")) do
+		if i:get_count() == 0 then
+			free_slots = free_slots+1
+		end
+	end
+	if free_slots < 2 then
+		return false
+	end
+	return true
+end
+
+local drop_mushroom = minetest.registered_nodes["riesenpilz:nether_shroom"].on_drop
+minetest.override_item("riesenpilz:nether_shroom", {
+	on_drop = function(itemstack, dropper, pos)
+		if dropper:get_player_control().aux1 then
+			return drop_mushroom(itemstack, dropper, pos)
+		end
+		local inv = dropper:get_inventory()
+		if not inv then
+			return
+		end
+		if not room_for_items(inv) then
+			return
+		end
+		minetest.sound_play("nether_remove_leaf", {pos = pos,  gain = 0.25})
+		itemstack:take_item()
+		inv:add_item("main", "nether:shroom_head")
+		inv:add_item("main", "nether:shroom_stem")
+		return itemstack
+	end,
+})
+
+minetest.register_node("nether:apple", {
+	description = "Nether Fruit",
+	drawtype = "nodebox",
+	tiles = {"nether_fruit_top.png", "nether_fruit_bottom.png",
+		"nether_fruit.png", "nether_fruit.png^[transformFX",
+		"nether_fruit.png^[transformFX", "nether_fruit.png"},
+	use_texture_alpha = "opaque",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{-1/6, -1/4, -1/6, 1/6, -1/6, 1/6},
+
+			{-1/6, -1/6, -1/4, 1/6, 1/6, 1/4},
+			{-1/4, -1/6, -1/6, 1/4, 1/6, 1/6},
+
+			{-1/4, 1/6, -1/12, 1/4, 1/4, 1/12},
+			{-1/12, 1/6, -1/4, 1/12, 1/4, 1/4},
+
+			{-1/6, 1/6, -1/6, 1/6, 1/3, 1/6},
+
+			{-1/12, 1/3, -1/12, 0, 5/12, 0},
+
+			{-1/12, 5/12, -1/6, 0, 0.5, 1/12},
+			{-1/6, 5/12, -1/12, 1/12, 0.5, 0},
+		}
+	},
+	paramtype = "light",
+	groups = {fleshy=3, dig_immediate=3},
+	on_use = function(itemstack, user)
+		local inv = user:get_inventory()
+		if not inv then
+			return
+		end
+		itemstack:take_item()
+		if nether.teleport_player(user) then
+			return itemstack
+		end
+		local amount = math.random(4, 6)
+		inv:add_item("main", {name="nether:blood_extracted", count=math.floor(amount/3)})
+		user:set_hp(user:get_hp()-amount)
+		return itemstack
+	end,
+	sounds = default.node_sound_defaults(),
+	furnace_burntime = 6,
+})
+
+local drop_fruit = minetest.registered_nodes["nether:apple"].on_drop
+minetest.override_item("nether:apple", {
+	on_drop = function(itemstack, dropper, pos)
+		if dropper:get_player_control().aux1 then
+			return drop_fruit(itemstack, dropper, pos)
+		end
+		local inv = dropper:get_inventory()
+		if not inv then
+			return
+		end
+		if not room_for_items(inv) then
+			return
+		end
+		minetest.sound_play("nether_remove_leaf", {pos = pos,  gain = 0.25})
+		itemstack:take_item()
+		inv:add_item("main", "nether:fruit_leaf")
+		inv:add_item("main", "nether:fruit_no_leaf")
+		return itemstack
+	end,
+})
+
+-- Nether vine
+minetest.register_node("nether:vine", {
+	description = "Nether vine",
+	walkable = false,
+	drop = "nether:sapling",
+	sunlight_propagates = true,
+	paramtype = "light",
+	tiles = { "nether_vine.png" },
+	drawtype = "plantlike",
+	inventory_image = "nether_vine.png",
+	groups = { snappy = 3,flammable=2 },
+	sounds = default.node_sound_leaves_defaults(),
+	after_dig_node = function(pos, _, _, digger)
+		if digger then
+			local p = {x=pos.x, y=pos.y-1, z=pos.z}
+			local nn = minetest.get_node(p)
+			if nn.name == "nether:vine" then
+				minetest.node_dig(p, nn, digger)
+			end
+		end
+	end
+})
+
+
+-- forest stuff
+
+for n,i in pairs({"small", "middle", "big"}) do
+	minetest.register_node("nether:grass_"..i, {
+		description = "Nether Grass",
+		drawtype = "plantlike",
+		waving = 1,
+		tiles = {"nether_grass_"..i..".png"},
+		inventory_image = "nether_grass_"..i..".png",
+		wield_image = "nether_grass_"..i..".png",
+		paramtype = "light",
+		walkable = false,
+		buildable_to = true,
+		drop = "nether:grass "..n,
+		groups = {snappy=3,flora=1,attached_node=1},
+		sounds = default.node_sound_leaves_defaults(),
+		selection_box = {
+			type = "fixed",
+			fixed = {-0.5, -0.5, -0.5, 0.5, -5/16, 0.5},
+		},
+	})
+end
+
+minetest.register_node("nether:glowflower", {
+	description = "Glowing Flower",
+	drawtype = "plantlike",
+	tiles = {"nether_glowflower.png"},
+	inventory_image = "nether_glowflower.png",
+	wield_image = "nether_glowflower.png",
+	sunlight_propagates = true,
+	paramtype = "light",
+	walkable = false,
+	buildable_to = true,
+	light_source = 10,
+	groups = {snappy=3,flammable=2,flower=1,flora=1,attached_node=1},
+	sounds = default.node_sound_leaves_defaults(),
+	selection_box = {
+		type = "fixed",
+		fixed = { -0.15, -0.5, -0.15, 0.15, 0.2, 0.15 },
+	},
+})
+
+minetest.register_node("nether:tree_sapling", {
+	description = "Nether Tree Sapling",
+	drawtype = "plantlike",
+	tiles = {"nether_tree_sapling.png"},
+	inventory_image = "nether_tree_sapling.png",
+	wield_image = "nether_tree_sapling.png",
+	paramtype = "light",
+	walkable = false,
+	selection_box = {
+		type = "fixed",
+		fixed = {-0.3, -0.5, -0.3, 0.3, 0.35, 0.3}
+	},
+	groups = {snappy=2, oddly_breakable_by_hand=2, attached_node=1},
+	sounds = default.node_sound_leaves_defaults(),
+})
+
+minetest.register_node("nether:tree", {
+	description = "Nether Trunk",
+	tiles = {"nether_tree_top.png", "nether_tree_top.png", "nether_tree.png"},
+	paramtype2 = "facedir",
+	is_ground_content = false,
+	groups = {tree=1,choppy=2,oddly_breakable_by_hand=1},
+	sounds = default.node_sound_wood_defaults(),
+	on_place = minetest.rotate_node
+})
+
+minetest.register_node("nether:tree_corner", {
+	description = "Nether Trunk Corner",
+	tiles = {"nether_tree.png^[transformR180", "nether_tree_top.png",
+		"nether_tree_corner.png^[transformFY",
+		"nether_tree_corner.png^[transformR180", "nether_tree.png",
+		"nether_tree_top.png"},
+	paramtype2 = "facedir",
+	is_ground_content = false,
+	groups = {tree=1,choppy=2,oddly_breakable_by_hand=1,not_in_creative_inventory=1},
+	drop = "nether:tree",
+	sounds = default.node_sound_wood_defaults(),
+	on_place = minetest.rotate_node
+})
+
+minetest.register_node("nether:forest_wood", {
+	description = "Nether Wood Block",
+	tiles = {"nether_forest_wood.png"},
+	groups = {choppy=2,oddly_breakable_by_hand=2,wood=1},
+	sounds = default.node_sound_wood_defaults(),
+})
+add_more_nodes("forest_wood")
+
+minetest.register_node("nether:leaves", {
+	description = "Nether Leaves",
+	drawtype = "plantlike",
+	waving = 1,
+	visual_scale = math.sqrt(2) + 0.01,
+	tiles = {"nether_leaves.png"},
+	inventory_image = "nether_leaves.png",
+	wield_image = "nether_leaves.png",
+	paramtype = "light",
+	paramtype2 = "degrotate",
+	is_ground_content = false,
+	groups = {snappy=3, leafdecay=3, leaves=1},
+	drop = {
+		max_items = 1,
+		items = {
+			{
+				items = {"nether:tree_sapling"},
+				rarity = 30,
+			},
+			{
+				items = {"nether:leaves"},
+			}
+		}
+	},
+	sounds = default.node_sound_leaves_defaults(),
+})
+
+minetest.register_node("nether:dirt", {
+	description = "Nether Dirt",
+	tiles = {"nether_dirt.png"},
+	groups = {crumbly=3,soil=1,nether_dirt=1},
+	sounds = default.node_sound_dirt_defaults(),
+})
+
+minetest.register_node("nether:dirt_top", {
+	description = "Nether Dirt Top",
+	tiles = {"nether_dirt_top.png", "nether_dirt.png",
+		{name="nether_dirt.png^nether_dirt_top_side.png", tileable_vertical = false}
+	},
+	groups = {crumbly=3,soil=1,nether_dirt=1},
+	drop = "nether:dirt",
+	sounds = default.node_sound_dirt_defaults({
+		footstep = {name="default_grass_footstep", gain=0.25},
+	}),
+})
+
+minetest.register_node("nether:dirt_bottom", {
+	description = "Netherrack Dirt Transition",
+	tiles = {"nether_dirt.png", "nether_netherrack.png",
+		{name="nether_netherrack.png^nether_dirt_transition.png", tileable_vertical = false}
+	},
+	groups = {nether=2},
+	drop = "nether:netherrack",
+	sounds = default.node_sound_dirt_defaults({
+		dig = {name="nether_dig", gain=0.7},
+		dug = {name="nether_dug", gain=1},
+	}),
+	can_dig = function(_, player)
+		return digging_allowed(player, 2)
+	end,
+})
+
+
+-- Nether torch
+minetest.register_node("nether:torch", {
+	description = "Nether Torch",
+	drawtype = "torchlike",
+	tiles = {"nether_torch_on_floor.png", "nether_torch_on_ceiling.png",
+		{
+			name = "nether_torch.png",
+			animation = {
+				type = "vertical_frames",
+				aspect_w = 16,
+				aspect_h = 16,
+				length = 2.0,
+			},
+		},
+	},
+	inventory_image = "nether_torch_on_floor.png",
+	wield_image = "nether_torch_on_floor.png",
+	paramtype = "light",
+	paramtype2 = "wallmounted",
+	sunlight_propagates = true,
+	walkable = false,
+	light_source = 13,
+	selection_box = {
+		type = "wallmounted",
+		wall_top = {-0.1, 0.5-0.6, -0.1, 0.1, 0.5, 0.1},
+		wall_bottom = {-0.1, -0.5, -0.1, 0.1, -0.5+0.6, 0.1},
+		wall_side = {-0.5, -0.3, -0.1, -0.5+0.3, 0.3, 0.1},
+	},
+	groups = {choppy=2, dig_immediate=3, attached_node=1, hot=3, igniter=1},
+	legacy_wallmounted = true,
+	sounds = default.node_sound_defaults(),
+})
+
+local invisible = "nether_transparent.png"
+minetest.register_node("nether:portal", {
+	description = "Nether Portal Essence",
+	tiles = {invisible, invisible, invisible, invisible, "nether_portal_stuff.png"},
+	inventory_image = "nether_portal_stuff.png",
+	wield_image = "nether_portal_stuff.png",
+	light_source = 12,
+	paramtype = "light",
+	sunlight_propagates = true,
+	use_texture_alpha = "blend",
+	walkable = false,
+	pointable = false,
+	buildable_to = false,
+	drop = "",
+	diggable = false,
+	groups = {not_in_creative_inventory=1},
+	post_effect_color = {a=200, r=50, g=0, b=60},--{a=180, r=128, g=0, b=128}
+	drawtype = "nodebox",
+	paramtype2 = "facedir",
+	node_box = {
+		type = "fixed",
+		fixed = {
+			{-0.5, -0.5, -0.1,  0.5, 0.5, 0.1},
+		},
+	},
+})
+
+
+minetest.register_craftitem("nether:grass", {
+	description = "Nether Grass",
+	inventory_image = "nether_grass.png",
+})
+
+minetest.register_craftitem("nether:grass_dried", {
+	description = "Dried Nether Grass",
+	inventory_image = "nether_grass_dried.png",
+	furnace_burntime = 1,
+})
+
+minetest.register_craftitem("nether:forest_planks", {
+	description = "Nether Wooden Planks",
+	inventory_image = "nether_forest_planks.png",
+	stack_max = 990,
+})
+
+minetest.register_craftitem("nether:bark", {
+	description = "Nether Trunk Bark",
+	inventory_image = "nether_bark.png",
+	furnace_burntime = 5,
+})
+
+-- Nether Pearl
+minetest.register_craftitem("nether:pearl", {
+	description = "Nether Pearl",
+	inventory_image = "nether_pearl.png",
+})
+
+minetest.register_craftitem("nether:stick", {
+	description = "Nether Stick",
+	inventory_image = "nether_stick.png",
+	groups = {stick=1},
+})
+
+local tmp = {}
+minetest.register_craftitem("nether:shroom_head", {
+	description = "Nether Mushroom Head",
+	inventory_image = "nether_shroom_top.png",
+	furnace_burntime = 3,
+	on_place = function(itemstack, _, pointed_thing)
+		if not pointed_thing then
+			return
+		end
+
+		if pointed_thing.type ~= "node" then
+			return
+		end
+
+		local pos = minetest.get_pointed_thing_position(pointed_thing)
+		local node = minetest.get_node(pos)
+		local pstr = pos.x.." "..pos.y.." "..pos.z
+
+		if node.name == "nether:netherrack_soil"
+		and not tmp[pstr] then
+			minetest.sound_play("default_grass_footstep", {pos=pos})
+			minetest.set_node(pos, {name="nether:netherrack_soil", param2=math.max(node.param2, math.random(3, 10))})
+			tmp[pstr] = true
+			minetest.after(3, function() tmp[pos.x.." "..pos.y.." "..pos.z] = nil end)
+		end
+	end
+})
+
+minetest.register_craftitem("nether:shroom_stem", {
+	description = "Nether Mushroom Stem",
+	inventory_image = "nether_shroom_stem.png",
+	furnace_burntime = 3,
+})
+
+minetest.register_craftitem("nether:fruit_leaf", {
+	description = "Nether Fruit Leaf",
+	inventory_image = "nether_fruit_leaf.png",
+	furnace_burntime = 2,
+})
+
+minetest.register_craftitem("nether:fruit_no_leaf", {
+	description = "Nether Fruit Without Leaf",
+	inventory_image = "nether_fruit_no_leaf.png",
+	furnace_burntime = 4,
+})
+
+minetest.register_craftitem("nether:fim", {
+	description = "Nether FIM",	--fruit in mushroom
+	inventory_image = "nether_fim.png",
+	furnace_burntime = 10,
+})
+
+local blood_exno = {}
+for _,i in ipairs({"nether:blood", "nether:blood_top", "nether:blood_stem"}) do
+	blood_exno[i] = i.."_empty"
+end
+
+minetest.register_craftitem("nether:blood_extracted", {
+	description = "Blood",
+	inventory_image = "nether_blood_extracted.png",
+	on_place = function(itemstack, _, pointed_thing)
+		if not pointed_thing then
+			return
+		end
+
+		if pointed_thing.type ~= "node" then
+			return
+		end
+
+		local pos = minetest.get_pointed_thing_position(pointed_thing)
+		local node = minetest.get_node_or_nil(pos)
+
+		if not node then
+			return
+		end
+
+		if node.name == "nether:vine" then
+			pos = {x=pos.x, y=pos.y-1, z=pos.z}
+			if minetest.get_node(pos).name == "air" then
+				minetest.set_node(pos, {name = "nether:vine"})
+			end
+			itemstack:take_item()
+			return itemstack
+		end
+
+		if node.name ~= "nether:extractor" then
+			return
+		end
+		itemstack:take_item()
+		minetest.after(1, function(pos)
+			for i = -1,1,2 do
+				for _,p in ipairs({
+					{x=pos.x+i, y=pos.y, z=pos.z},
+					{x=pos.x, y=pos.y, z=pos.z+i},
+				}) do
+					local nodename = blood_exno[minetest.get_node(p).name]
+					if nodename then
+						minetest.set_node(p, {name=nodename})
+						p = vector.add(p, {x=math.random()-0.5, y=math.random()+0.5, z=math.random()-0.5})
+						minetest.sound_play("nether_extract_blood", {pos = p,  gain = 1})
+						minetest.add_item(p, "nether:blood_extracted")
+					end
+				end
+			end
+		end, pos)
+
+		return itemstack
+	end
+})
+
+minetest.register_craftitem("nether:hotbed", {
+	description = "Cooked Blood",
+	inventory_image = "nether_hotbed.png",
+	on_place = function(itemstack, _, pointed_thing)
+		if not pointed_thing then
+			return
+		end
+		if pointed_thing.type ~= "node" then
+			return
+		end
+		local pos = minetest.get_pointed_thing_position(pointed_thing)
+		local node = minetest.get_node(pos)
+
+		if node.name ~= "nether:netherrack" then
+			return
+		end
+
+		minetest.sound_play("default_place_node", {pos=pos})
+		minetest.set_node(pos, {name = "nether:netherrack_soil"})
+
+		itemstack:take_item()
+		return itemstack
+	end
+})
+
+
+minetest.register_tool("nether:pick_mushroom", {
+	description = "Nether Mushroom Pickaxe",
+	inventory_image = "nether_pick_mushroom.png",
+	tool_capabilities = {
+		max_drop_level=0,
+		groupcaps={
+			cracky = {times={[3]=3}, uses=1, maxlevel=1},
+			nether = {times={[3]=3}, uses=1, maxlevel=1},
+		},
+	},
+})
+
+minetest.register_tool("nether:pick_wood", {
+	description = "Nether Wood Pickaxe",
+	inventory_image = "nether_pick_wood.png",
+	tool_capabilities = {
+		full_punch_interval = 1.2,
+		max_drop_level=0,
+		groupcaps={
+			cracky = {times={[3]=1.6}, uses=10, maxlevel=1},
+			nether = {times={[2]=6, [3]=1.6}, uses=10, maxlevel=1},
+		},
+		damage_groups = {fleshy=2},
+	},
+})
+
+minetest.register_tool("nether:pick_netherrack", {
+	description = "Netherrack Pickaxe",
+	inventory_image = "nether_pick_netherrack.png",
+	tool_capabilities = {
+		full_punch_interval = 1.3,
+		max_drop_level=0,
+		groupcaps={
+			cracky = {times={[2]=2.0, [3]=1.20}, uses=20, maxlevel=1},
+			nether = {times={[1]=16, [2]=2, [3]=1.20}, uses=20, maxlevel=1},
+		},
+		damage_groups = {fleshy=3},
+	},
+})
+
+minetest.register_tool("nether:pick_netherrack_blue", {
+	description = "Blue Netherrack Pickaxe",
+	inventory_image = "nether_pick_netherrack_blue.png",
+	tool_capabilities = {
+		full_punch_interval = 1.0,
+		max_drop_level=1,
+		groupcaps={
+			cracky = {times={[1]=4.00, [2]=1.60, [3]=0.80}, uses=30, maxlevel=2},
+			nether = {times={[1]=4.00, [2]=1.60, [3]=0.80}, uses=30, maxlevel=2},
+		},
+		damage_groups = {fleshy=4},
+	},
+})
+
+minetest.register_tool("nether:pick_white", {
+	description = "Siwtonic Pickaxe",
+	inventory_image = "nether_pick_white.png",
+	tool_capabilities = {
+		full_punch_interval = 0.9,
+		max_drop_level=3,
+		groupcaps={
+			cracky = {times={[1]=1, [2]=0.8, [3]=0.3}, uses=180, maxlevel=3},
+			nether = {times={[1]=1, [2]=0.5, [3]=0.3}, uses=180, maxlevel=3},
+		},
+		damage_groups = {fleshy=5},
+	},
+})
+
+minetest.register_tool("nether:axe_netherrack", {
+	description = "Netherrack Axe",
+	inventory_image = "nether_axe_netherrack.png",
+	tool_capabilities = {
+		full_punch_interval = 1.3,
+		max_drop_level=0,
+		groupcaps={
+			choppy={times={[1]=2.9, [2]=1.9, [3]=1.4}, uses=20, maxlevel=1},
+		},
+		damage_groups = {fleshy=4},
+	},
+})
+
+minetest.register_tool("nether:axe_netherrack_blue", {
+	description = "Blue Netherrack Axe",
+	inventory_image = "nether_axe_netherrack_blue.png",
+	tool_capabilities = {
+		full_punch_interval = 0.9,
+		max_drop_level=1,
+		groupcaps={
+			choppy={times={[1]=2.5, [2]=1.5, [3]=1}, uses=30, maxlevel=2},
+		},
+		damage_groups = {fleshy=6},
+	},
+})
+
+minetest.register_tool("nether:axe_white", {
+	description = "Siwtonic Axe",
+	inventory_image = "nether_axe_white.png",
+	tool_capabilities = {
+		full_punch_interval = 0.9,
+		max_drop_level=1,
+		groupcaps={
+			choppy={times={[1]=1.2, [2]=0.5, [3]=0.3}, uses=180, maxlevel=2},
+		},
+		damage_groups = {fleshy=8},
+	},
+})
+
+minetest.register_tool("nether:shovel_netherrack", {
+	description = "Netherrack Shovel",
+	inventory_image = "nether_shovel_netherrack.png",
+	wield_image = "nether_shovel_netherrack.png^[transformR90",
+	tool_capabilities = {
+		full_punch_interval = 1.4,
+		max_drop_level=0,
+		groupcaps={
+			crumbly = {times={[1]=1.7, [2]=1.1, [3]=0.45}, uses=22, maxlevel=2},
+		},
+		damage_groups = {fleshy=2},
+	},
+})
+
+minetest.register_tool("nether:shovel_netherrack_blue", {
+	description = "Blue Netherrack Shovel",
+	inventory_image = "nether_shovel_netherrack_blue.png",
+	wield_image = "nether_shovel_netherrack_blue.png^[transformR90",
+	tool_capabilities = {
+		full_punch_interval = 1.1,
+		max_drop_level=1,
+		groupcaps={
+			crumbly = {times={[1]=1.4, [2]=0.8, [3]=0.35}, uses=50, maxlevel=2},
+		},
+		damage_groups = {fleshy=3},
+	},
+})
+
+minetest.register_tool("nether:shovel_white", {
+	description = "Siwtonic Shovel",
+	inventory_image = "nether_shovel_white.png",
+	wield_image = "nether_shovel_white.png^[transformR90",
+	tool_capabilities = {
+		full_punch_interval = 1,
+		max_drop_level=1,
+		groupcaps={
+			crumbly = {times={[1]=0.95, [2]=0.45, [3]=0.1}, uses=151, maxlevel=3},
+		},
+		damage_groups = {fleshy=4},
+	},
+})
+
+minetest.register_tool("nether:sword_netherrack", {
+	description = "Netherrack Sword",
+	inventory_image = "nether_sword_netherrack.png",
+	tool_capabilities = {
+		full_punch_interval = 1,
+		max_drop_level=0,
+		groupcaps={
+			snappy={times={[2]=1.3, [3]=0.38}, uses=40, maxlevel=1},
+		},
+		damage_groups = {fleshy=5},
+	},
+})
+
+minetest.register_tool("nether:sword_netherrack_blue", {
+	description = "Blue Netherrack Sword",
+	inventory_image = "nether_sword_netherrack_blue.png",
+	tool_capabilities = {
+		full_punch_interval = 0.8,
+		max_drop_level=1,
+		groupcaps={
+			snappy={times={[1]=2.5, [2]=1.1, [3]=0.33}, uses=40, maxlevel=2},
+		},
+		damage_groups = {fleshy=7},
+	},
+})
+
+minetest.register_tool("nether:sword_white", {
+	description = "Siwtonic Sword",
+	inventory_image = "nether_sword_white.png",
+	wield_image = "nether_sword_white.png^[transformR90",
+	tool_capabilities = {
+		full_punch_interval = 0.7,
+		max_drop_level=1,
+		groupcaps={
+			snappy={times={[1]=1.7, [2]=0.8, [3]=0.2}, uses=100, maxlevel=3},
+		},
+		damage_groups = {fleshy=11},
+	},
+})
+
+
+-- override creative hand
+if minetest.settings:get_bool("creative_mode") then
+	local capas = minetest.registered_items[""].tool_capabilities
+	capas.groupcaps.nether = capas.groupcaps.cracky
+	minetest.override_item("", {tool_capabilities = capas})
+end
diff --git a/nether/nether/mod.conf b/nether/nether/mod.conf
new file mode 100644
index 00000000..eb8e675d
--- /dev/null
+++ b/nether/nether/mod.conf
@@ -0,0 +1,3 @@
+name = nether
+depends = default,glow,riesenpilz,stairs,vector_extras
+optional_depends = creative,fence_registration,function_delayer,watershed
diff --git a/nether/nether/pearl.lua b/nether/nether/pearl.lua
new file mode 100644
index 00000000..236efce1
--- /dev/null
+++ b/nether/nether/pearl.lua
@@ -0,0 +1,190 @@
+
+local function throw_pearl(item, player)
+	local playerpos = player:get_pos()
+	playerpos.y = playerpos.y+1.625
+	local obj = minetest.add_entity(playerpos, "nether:pearl_entity")
+	local dir = player:get_look_dir()
+	obj:setvelocity(vector.multiply(dir, 30))
+	obj:setacceleration({x=dir.x*-3, y=-dir.y^8*80-10, z=dir.z*-3})
+	local pname = player:get_player_name()
+	obj:get_luaentity().player = pname
+	if not minetest.is_creative_enabled(pname) then
+		item:take_item()
+		return item
+	end
+end
+
+local function get_node(pos)
+	local name = minetest.get_node(pos).name
+	if name ~= "ignore" then
+		return name
+	end
+	minetest.get_voxel_manip():read_from_map(pos, pos)
+	name = minetest.get_node_or_nil(pos)
+	if not name then
+		return
+	end
+	return name.name
+end
+
+local softs = {}
+local function is_soft(pos)
+	local name = get_node(pos)
+	if not name then
+		return false
+	end
+	local is_soft = softs[name]
+	if is_soft ~= nil then
+		return is_soft
+	end
+	if not minetest.registered_nodes[name] then
+		softs[name] = false
+		return false
+	end
+	is_soft = minetest.registered_nodes[name].walkable == false
+	softs[name] = is_soft
+	return is_soft
+end
+
+-- teleports the player there if there's free space
+local function teleport_player(pos, player)
+	if not is_soft(pos) then
+		return false
+	end
+	if not is_soft({x=pos.x, y=pos.y+1, z=pos.z})
+	and not is_soft({x=pos.x, y=pos.y-1, z=pos.z}) then
+		return false
+	end
+	pos.y = pos.y+0.05
+	player:moveto(pos)
+	return true
+end
+
+--[[
+local dg_ps = {}
+local function forceload(pos)
+	dg_ps[#dg_ps+1] = pos
+	minetest.forceload_block(pos)
+	minetest.after(5, function(pos)
+		minetest.forceload_free_block(pos)
+		for i,p in pairs(dg_ps) do
+			if vector.equals(p, pos) then
+				dg_ps[i] = nil
+				return
+			end
+		end
+	end, pos)
+end
+minetest.register_on_shutdown(function()
+	for _,p in pairs(dg_ps) do
+		minetest.forceload_free_block(p)
+	end
+end)--]]
+
+minetest.register_entity("nether:pearl_entity", {
+	collisionbox = {0,0,0,0,0,0}, --not pointable
+	visual_size = {x=0.1, y=0.1},
+	physical = false, -- Collides with things
+	textures = {"nether_pearl.png"},
+	on_activate = function(self, staticdata)
+		if not staticdata
+		or staticdata == "" then
+			return
+		end
+		local tmp = minetest.deserialize(staticdata)
+		if not tmp then
+			minetest.log("error", "[nether] pearl: invalid staticdata ")
+			return
+		end
+		self.player = tmp.player
+	end,
+	get_staticdata = function(self)
+		--forceload(vector.round(self.object:get_pos()))
+		return minetest.serialize({
+			player = self.player,
+		})
+	end,
+	timer = 0,
+	on_step = function(self, dtime)
+		self.timer = self.timer+dtime
+
+	--[[
+		local delay = self.delay
+		if delay < 0.1 then
+			self.delay = delay+dtime
+			return
+		end
+		self.delay = 0--]]
+
+		if self.timer > 20 then
+			self.object:remove()
+			return
+		end
+
+		local pos = self.object:get_pos()
+		local rpos = vector.round(pos)
+		local lastpos = self.lastpos
+		if not lastpos then
+			self.lastpos = vector.new(rpos)
+			return
+		end
+		if lastpos.x
+		and vector.equals(vector.round(lastpos), rpos) then
+			return
+		end
+
+		local player = self.player
+		if not player then
+			minetest.log("error", "[nether] pearl: missing playername")
+			self.object:remove()
+			return
+		end
+		player = minetest.get_player_by_name(player)
+		if not player then
+			minetest.log("error", "[nether] pearl: missing player")
+			self.object:remove()
+			return
+		end
+
+		if not get_node(rpos) then
+			minetest.log("error", "[nether] pearl: missing node")
+			self.object:remove()
+			return
+		end
+
+		self.lastpos = vector.new(pos)
+
+		local free, p = minetest.line_of_sight(lastpos, pos)
+		if free then
+			return
+		end
+		if is_soft(p) then
+			return
+		end
+		self.object:remove()
+		minetest.after(0, function(p) --minetest.after is used that the sound is played after the teleportation
+			minetest.sound_play("nether_pearl", {pos=p, max_hear_distance=10})
+		end, p)
+		p.y = p.y+1
+		if teleport_player(vector.new(p), player) then
+			return
+		end
+		p.y = p.y-2
+		for i = -1,1,2 do
+			for _,j in pairs({{i, 0}, {0, i}}) do
+				if teleport_player({x=p.x+j[1], y=p.y, z=p.z+j[2]}, player) then
+					return
+				end
+			end
+		end
+		for i = -1,1,2 do
+			for j = -1,1,2 do
+				if teleport_player({x=p.x+j, y=p.y, z=p.z+i}, player) then
+					return
+				end
+			end
+		end
+	end
+})
+
+minetest.override_item("nether:pearl", {on_use = throw_pearl})
diff --git a/nether/nether/portal.lua b/nether/nether/portal.lua
new file mode 100644
index 00000000..619e64f7
--- /dev/null
+++ b/nether/nether/portal.lua
@@ -0,0 +1,697 @@
+--code copied from Pilzadam's nether mod and edited
+
+-- kills the player if he uses PilzAdam portal
+local portal_target = nether.buildings+1
+local nether_prisons = minetest.settings:get_bool("enable_damage")
+local obsidian_portal_kills = nether_prisons and true
+local mclike_portal = false
+
+local abm_allowed
+minetest.after(5, function()
+	abm_allowed = true
+end)
+
+local save_path = minetest.get_worldpath() .. "/nether_players"
+local players_in_nether = {}
+-- only get info from file if nether prisons
+if nether_prisons then
+	local file = io.open(save_path, "r")
+	if not file then
+		return
+	end
+	local contents = file:read"*all"
+	io.close(file)
+	if not contents then
+		return
+	end
+	local playernames = string.split(contents, " ")
+	for i = 1,#playernames do
+		players_in_nether[playernames[i]] = true
+	end
+end
+
+local function save_nether_players()
+	local playernames,n = {},1
+	for name in pairs(players_in_nether) do
+		playernames[n] = name
+		n = n+1
+	end
+	local f = io.open(save_path, "w")
+	assert(f, "Could not open nether_players file for writing.")
+	f:write(table.concat(playernames, " "))
+	io.close(f)
+end
+
+local update_background
+if nether_prisons then
+	function update_background(player, down)
+		if down then
+			player:set_sky({r=15, g=0, b=0}, "plain")
+		else
+			player:set_sky(nil, "regular")
+		end
+	end
+else
+	function update_background()end
+end
+
+-- returns nodename if area is generated, else calls generation function
+local function generated_or_generate(pos)
+	local node = minetest.get_node_or_nil(pos)
+	if node then
+		return node.name
+	end
+	minetest.get_voxel_manip():read_from_map(pos, pos)
+	node = minetest.get_node_or_nil(pos)
+	if not node then
+		minetest.emerge_area(vector.subtract(pos, 80), vector.add(pos, 80))
+		return false
+	end
+	return node.name
+end
+
+-- where the player appears after dying
+local function get_player_died_target(player)
+	local target = vector.add(player:get_pos(),
+		{x=math.random(-100,100), y=0, z=math.random(-100,100)})
+	target.y = portal_target + math.random(4)
+	return target
+end
+
+-- used for obsidian portal
+local function obsidian_teleport(player, pname, target)
+	minetest.chat_send_player(pname, "For any reason you arrived here. Type " ..
+		"/nether_help to find out things like craft recipes.")
+	players_in_nether[pname] = true
+	save_nether_players()
+	update_background(player, true)
+	if target then
+		player:set_pos(target)
+	else
+		player:set_hp(0)
+	end
+end
+
+-- teleports players to nether or helps it
+local function player_to_nether(player, pos)
+	local pname = player:get_player_name()
+	if players_in_nether[pname] then
+		return
+	end
+	players_in_nether[pname] = true
+	save_nether_players()
+	update_background(player, true)
+	if pos then
+		player:set_pos(pos)
+		return
+	end
+	minetest.chat_send_player(pname, "For any reason you arrived here. " ..
+		"Type /nether_help to find out things like craft recipes.")
+	player:set_hp(0)
+	if not nether_prisons then
+		player:set_pos(get_player_died_target(player))
+	end
+end
+
+local function player_from_nether(player, pos)
+	local pname = player:get_player_name()
+	if players_in_nether[pname] then
+		players_in_nether[pname] = nil
+		save_nether_players()
+	end
+	update_background(player)
+	player:set_pos(pos)
+end
+
+
+local function player_exists(name)
+	local players = minetest.get_connected_players()
+	for i = 1,#players do
+		if players[i]:get_player_name() == name then
+			return true
+		end
+	end
+	return false
+end
+
+-- Chatcommands (edited) written by sss
+minetest.register_chatcommand("to_hell", {
+	params = "[<player_name>]",
+	description = "Send someone to hell",
+	func = function(name, pname)
+		if not minetest.check_player_privs(name, {nether=true}) then
+			return false,
+				"You need the nether privilege to execute this chatcommand."
+		end
+		if not player_exists(pname) then
+			pname = name
+		end
+		local player = minetest.get_player_by_name(pname)
+		if not player then
+			return false, "Something went wrong."
+		end
+		minetest.chat_send_player(pname, "Go to hell !!!")
+		player_to_nether(player)
+		return true, pname.." is now in the nether."
+	end
+})
+
+minetest.register_chatcommand("from_hell", {
+	params = "[<player_name>]",
+	description = "Extract from hell",
+	func = function(name, pname)
+		if not minetest.check_player_privs(name, {nether=true}) then
+			return false,
+				"You need the nether priv to execute this chatcommand."
+		end
+		if not player_exists(pname) then
+			pname = name
+		end
+		local player = minetest.get_player_by_name(pname)
+		if not player then
+			return false, "Something went wrong."
+		end
+		minetest.chat_send_player(pname, "You are free now")
+		local pos = player:get_pos()
+		player_from_nether(player, {x=pos.x, y=100, z=pos.z})
+		return true, pname.." is now out of the nether."
+	end
+})
+
+
+if nether_prisons then
+	-- randomly set player position when he/she dies in nether
+	minetest.register_on_respawnplayer(function(player)
+		local pname = player:get_player_name()
+		if not players_in_nether[pname] then
+			return
+		end
+		local target = get_player_died_target(player)
+		player:set_pos(target)
+		minetest.after(0, function(pname, target)
+			-- fixes respawn bug
+			local player = minetest.get_player_by_name(pname)
+			if player then
+				player:moveto(target)
+			end
+		end, pname, target)
+		return true
+	end)
+
+	-- override set_pos etc. to disallow player teleportion by e.g. travelnet
+	local function can_teleport(player, pos)
+		if not player:is_player() then
+			-- the same metatable is used for entities
+			return true
+		end
+		local pname = player:get_player_name()
+		local in_nether = players_in_nether[pname] == true
+
+		-- test if the target is valid
+		if pos.y < nether.start then
+			if in_nether then
+				return true
+			end
+		elseif not in_nether then
+			return true
+		end
+
+		-- test if the current position is valid
+		local current_pos = player:get_pos()
+		local now_in_nether = current_pos.y < nether.start
+		if now_in_nether ~= in_nether then
+			if in_nether then
+				minetest.log("action", "Player \"" .. pname ..
+					"\" has to be in the nether, teleporting it!")
+				update_background(player, true)
+				current_pos.y = portal_target
+				player:set_pos(current_pos)
+			else
+				minetest.log("action", "Player \"" .. pname ..
+					"\" must not be in the nether, teleporting it!")
+				update_background(player)
+				current_pos.y = 20
+				player:set_pos(current_pos)
+			end
+			return false
+		end
+
+		minetest.chat_send_player(pname,
+			"You can not simply teleport to or from the nether!")
+		minetest.log("action", "Player \"" .. pname ..
+			"\" attempted to teleport from or to the nether, ignoring.")
+		return false
+	end
+	local methods = {"set_pos", "move_to", "setpos", "moveto"}
+	local metatable_overridden
+	minetest.register_on_joinplayer(function(player)
+		-- set the background when the player joins
+		if player:get_pos().y < nether.start then
+			update_background(player, true)
+		end
+
+		-- overide set_pos etc. if not yet done
+		if metatable_overridden then
+			return
+		end
+		metatable_overridden = true
+		local mt = getmetatable(player)
+		for i = 1,#methods do
+			local methodname = methods[i]
+			local origfunc = mt[methodname]
+			mt[methodname] = function(...)
+				if can_teleport(...) then
+					origfunc(...)
+				end
+			end
+		end
+	end)
+else
+	-- test if player is in nether when he/she joins
+	minetest.register_on_joinplayer(function(player)
+		players_in_nether[player:get_player_name()] =
+			player:get_pos().y < nether.start or nil
+	end)
+end
+
+-- removes the violet stuff from the obsidian portal
+local function remove_portal_essence(pos)
+	for z = -1,1 do
+		for y = -2,2 do
+			for x = -1,1 do
+				local p = {x=pos.x+x, y=pos.y+y, z=pos.z+z}
+				if minetest.get_node(p).name == "nether:portal" then
+					minetest.remove_node(p)
+				end
+			end
+		end
+	end
+end
+
+-- change parts of the particledefinition instead of recreating it every time
+local particledef = {
+	amount = 32,
+	time = 4,
+	minvel = {x=0, y=1, z=0},
+	maxvel = {x=0, y=2, z=0},
+	minacc = {x=-0.5,y=-3,z=-0.3},
+	maxacc = {x=0.5,y=-0.4,z=0.3},
+	minexptime = 1,
+	maxexptime = 1,
+	minsize = 0.4,
+	maxsize = 3,
+	collisiondetection = true,
+}
+
+-- teleports player to neter (obsidian portal)
+local function obsi_teleport_player(player, pos, target)
+	local pname = player:get_player_name()
+	if players_in_nether[pname] then
+		return
+	end
+
+	local objpos = player:get_pos()
+	objpos.y = objpos.y+0.1 -- Fix some glitches at -8000
+	if minetest.get_node(vector.round(objpos)).name ~= "nether:portal" then
+		return
+	end
+
+	local has_teleported
+	if obsidian_portal_kills then
+		obsidian_teleport(player, pname)
+		has_teleported = true
+	elseif not mclike_portal then
+		local target = vector.round(get_player_died_target(player))
+		if generated_or_generate(target) then
+			obsidian_teleport(player, pname, target)
+			has_teleported = true
+		end
+	end
+
+	if not has_teleported then
+		-- e.g. ungenerated area
+		return
+	end
+
+	remove_portal_essence(pos)
+
+	minetest.sound_play("nether_portal_usual", {to_player=pname, gain=1})
+end
+
+-- abm for particles of the obsidian portal essence and for teleporting
+minetest.register_abm({
+	nodenames = {"nether:portal"},
+	interval = 1,
+	chance = 2,
+	catch_up = false,
+	action = function(pos, node)
+		if not abm_allowed then
+			return
+		end
+		particledef.minpos = {x=pos.x-0.25, y=pos.y-0.5, z=pos.z-0.25}
+		particledef.maxpos = {x=pos.x+0.25, y=pos.y+0.34, z=pos.z+0.25}
+		particledef.texture = "nether_portal_particle.png^[transform" ..
+			math.random(0, 7)
+		minetest.add_particlespawner(particledef)
+		for _,obj in pairs(minetest.get_objects_inside_radius(pos, 1)) do
+			if obj:is_player() then
+				local meta = minetest.get_meta(pos)
+				local target = minetest.string_to_pos(meta:get_string("target"))
+				if target then
+					minetest.after(3, obsi_teleport_player, obj, pos, target)
+				end
+			end
+		end
+	end,
+})
+
+local function move_check(p1, max, dir)
+	local p = {x=p1.x, y=p1.y, z=p1.z}
+	local d = math.abs(max-p1[dir]) / (max-p1[dir])
+	while p[dir] ~= max do
+		p[dir] = p[dir] + d
+		if minetest.get_node(p).name ~= "default:obsidian" then
+			return false
+		end
+	end
+	return true
+end
+
+local function check_portal(p1, p2)
+	if p1.x ~= p2.x then
+		if not move_check(p1, p2.x, "x") then
+			return false
+		end
+		if not move_check(p2, p1.x, "x") then
+			return false
+		end
+	elseif p1.z ~= p2.z then
+		if not move_check(p1, p2.z, "z") then
+			return false
+		end
+		if not move_check(p2, p1.z, "z") then
+			return false
+		end
+	else
+		return false
+	end
+
+	if not move_check(p1, p2.y, "y") then
+		return false
+	end
+	if not move_check(p2, p1.y, "y") then
+		return false
+	end
+
+	return true
+end
+
+-- tests if it's an obsidian portal
+local function is_portal(pos)
+	for d=-3,3 do
+		for y=-4,4 do
+			local px = {x=pos.x+d, y=pos.y+y, z=pos.z}
+			local pz = {x=pos.x, y=pos.y+y, z=pos.z+d}
+			if check_portal(px, {x=px.x+3, y=px.y+4, z=px.z}) then
+				return px, {x=px.x+3, y=px.y+4, z=px.z}
+			end
+			if check_portal(pz, {x=pz.x, y=pz.y+4, z=pz.z+3}) then
+				return pz, {x=pz.x, y=pz.y+4, z=pz.z+3}
+			end
+		end
+	end
+end
+
+-- put here the function for creating a second portal
+local create_second_portal
+if mclike_portal then
+	function create_second_portal(target)
+		-- change target here
+	end
+end
+
+-- adds the violet portal essence
+local function make_portal(pos)
+	local p1, p2 = is_portal(pos)
+	if not p1
+	or not p2 then
+		print("[nether] something failed.")
+		return false
+	end
+
+	local in_nether = p1.y < nether.start
+
+	if in_nether
+	and not mclike_portal then
+		print("[nether] aborted, obsidian portals can't be used to get out")
+		return
+	end
+
+	for d=1,2 do
+	for y=p1.y+1,p2.y-1 do
+		local p
+		if p1.z == p2.z then
+			p = {x=p1.x+d, y=y, z=p1.z}
+		else
+			p = {x=p1.x, y=y, z=p1.z+d}
+		end
+		if minetest.get_node(p).name ~= "air" then
+			return false
+		end
+	end
+	end
+
+	local param2
+	if p1.z == p2.z then
+		param2 = 0
+	else
+		param2 = 1
+	end
+
+	local target = {x=p1.x, y=p1.y, z=p1.z}
+	target.x = target.x + 1
+	if in_nether then
+		target.y = 0
+		create_second_portal(target)
+	else
+		target.y = portal_target + math.random(4)
+	end
+
+	if not generated_or_generate(target)
+	and mclike_portal then
+		return false
+	end
+
+	for d=0,3 do
+	for y=p1.y,p2.y do
+		local p
+		if param2 == 0 then
+			p = {x=p1.x+d, y=y, z=p1.z}
+		else
+			p = {x=p1.x, y=y, z=p1.z+d}
+		end
+		if minetest.get_node(p).name == "air" then
+			minetest.set_node(p, {name="nether:portal", param2=param2})
+		end
+		local meta = minetest.get_meta(p)
+		meta:set_string("p1", minetest.pos_to_string(p1))
+		meta:set_string("p2", minetest.pos_to_string(p2))
+		meta:set_string("target", minetest.pos_to_string(target))
+	end
+	end
+	print("[nether] construction accepted.")
+	return true
+end
+
+-- destroy the portal when destroying obsidian
+minetest.override_item("default:obsidian", {
+	on_destruct = function(pos)
+		local meta = minetest.get_meta(pos)
+		local p1 = minetest.string_to_pos(meta:get_string("p1"))
+		local p2 = minetest.string_to_pos(meta:get_string("p2"))
+		local target = minetest.string_to_pos(meta:get_string("target"))
+		if not p1 or not p2 then
+			return
+		end
+		for x=p1.x,p2.x do
+		for y=p1.y,p2.y do
+		for z=p1.z,p2.z do
+			local nn = minetest.get_node({x=x,y=y,z=z}).name
+			if nn == "default:obsidian" or nn == "nether:portal" then
+				if nn == "nether:portal" then
+					minetest.remove_node({x=x,y=y,z=z})
+				end
+				local m = minetest.get_meta({x=x,y=y,z=z})
+				m:set_string("p1", "")
+				m:set_string("p2", "")
+				m:set_string("target", "")
+			end
+		end
+		end
+		end
+		meta = minetest.get_meta(target)
+		if not meta then
+			return
+		end
+		p1 = minetest.string_to_pos(meta:get_string("p1"))
+		p2 = minetest.string_to_pos(meta:get_string("p2"))
+		if not p1 or not p2 then
+			return
+		end
+		for x=p1.x,p2.x do
+		for y=p1.y,p2.y do
+		for z=p1.z,p2.z do
+			local nn = minetest.get_node({x=x,y=y,z=z}).name
+			if nn == "default:obsidian" or nn == "nether:portal" then
+				if nn == "nether:portal" then
+					minetest.remove_node({x=x,y=y,z=z})
+				end
+				local m = minetest.get_meta({x=x,y=y,z=z})
+				m:set_string("p1", "")
+				m:set_string("p2", "")
+				m:set_string("target", "")
+			end
+		end
+		end
+		end
+	end
+})
+
+-- override mese crystal fragment for making an obsidian portal
+minetest.after(0.1, function()
+	minetest.override_item("default:mese_crystal_fragment", {
+		on_place = function(stack, player, pt)
+			if pt.under
+			and minetest.get_node(pt.under).name == "default:obsidian" then
+				local done = make_portal(pt.under)
+				if done then
+					minetest.chat_send_player(player:get_player_name(),
+						"Warning: If you are in the nether you may not be " ..
+						"able to find the way out!")
+					if not minetest.settings:get_bool("creative_mode") then
+						stack:take_item()
+					end
+				end
+			end
+			return stack
+		end
+	})
+end)
+
+
+-- a not filled square
+local function vector_square(r)
+	local tab, n = {}, 1
+	for i = -r+1, r do
+		for j = -1, 1, 2 do
+			local a, b = r*j, i*j
+			tab[n] = {a, b}
+			tab[n+1] = {b, a}
+			n=n+2
+		end
+	end
+	return tab
+end
+
+local function is_netherportal(pos)
+	local x, y, z = pos.x, pos.y, pos.z
+	for _,i in pairs({-1, 3}) do
+		if minetest.get_node({x=x, y=y+i, z=z}).name ~= "nether:white" then
+			return
+		end
+	end
+	for _,sn in pairs(vector_square(1)) do
+		if minetest.get_node({x=x+sn[1], y=y-1, z=z+sn[2]}).name ~= "nether:netherrack"
+		or minetest.get_node({x=x+sn[1], y=y+3, z=z+sn[2]}).name ~= "nether:blood_cooked" then
+			return
+		end
+	end
+	for _,sn in pairs(vector_square(2)) do
+		if minetest.get_node({x=x+sn[1], y=y-1, z=z+sn[2]}).name ~= "nether:netherrack_black"
+		or minetest.get_node({x=x+sn[1], y=y+3, z=z+sn[2]}).name ~= "nether:wood_empty" then
+			return
+		end
+	end
+	for i = -1,1,2 do
+		for j = -1,1,2 do
+			if minetest.get_node({x=x+i, y=y+2, z=z+j}).name ~= "nether:apple" then
+				return
+			end
+		end
+	end
+	for i = -2,2,4 do
+		for j = 0,2 do
+			for k = -2,2,4 do
+				if minetest.get_node({x=x+i, y=y+j, z=z+k}).name ~= "nether:netherrack_brick_blue" then
+					return
+				end
+			end
+		end
+	end
+	for i = -1,1 do
+		for j = -1,1 do
+			if minetest.get_node({x=x+i, y=y+4, z=z+j}).name ~= "nether:wood_empty" then
+				return
+			end
+		end
+	end
+	return true
+end
+
+-- cache known portals
+local known_portals_d = {}
+local known_portals_u = {}
+local function get_portal(t, z,x)
+	return t[z] and t[z][x]
+end
+local function set_portal(t, z,x, y)
+	t[z] = t[z] or {}
+	t[z][x] = y
+end
+
+-- used when a player eats that fruit in a portal
+function nether.teleport_player(player)
+	if not player then
+		minetest.log("error", "[nether] Missing player.")
+		return
+	end
+	local pos = vector.round(player:get_pos())
+	if not is_netherportal(pos) then
+		return
+	end
+	minetest.sound_play("nether_teleporter", {pos=pos})
+	local meta = minetest.get_meta({x=pos.x, y=pos.y-1, z=pos.z})
+	if pos.y < nether.start then
+		set_portal(known_portals_d, pos.z,pos.x, pos.y)
+
+		local my = tonumber(meta:get_string("y"))
+		local y = get_portal(known_portals_u, pos.z,pos.x)
+		if y then
+			if y ~= my then
+				meta:set_string("y", y)
+			end
+		else
+			y = my or 100
+		end
+		pos.y = y - 0.3
+
+		player_from_nether(player, pos)
+	else
+		set_portal(known_portals_u, pos.z,pos.x, pos.y)
+
+		local my = tonumber(meta:get_string("y"))
+		local y = get_portal(known_portals_d, pos.z,pos.x)
+		if y then
+			if y ~= my then
+				meta:set_string("y", y)
+			end
+		else
+			y = my or portal_target+math.random(4)
+		end
+		pos.y = y - 0.3
+
+		player_to_nether(player, pos)
+	end
+	minetest.sound_play("nether_teleporter", {pos=pos})
+	return true
+end
diff --git a/nether/nether/weird_mapgen_noise.lua b/nether/nether/weird_mapgen_noise.lua
new file mode 100644
index 00000000..8fe436db
--- /dev/null
+++ b/nether/nether/weird_mapgen_noise.lua
@@ -0,0 +1,90 @@
+--V2
+local function get_random(a, b, seed)
+	return PseudoRandom(math.abs(a+b*5)+seed)
+end
+
+local r_chs = {}
+
+local function nether_weird_noise(minp, fct, s, seed, range, scale)
+	if not r_chs[s] then
+		r_chs[s] = math.floor(s/3+0.5)
+	end
+	scale = scale or 15
+	local r_ch = r_chs[s]
+	local maxp = vector.add(minp, scale)
+
+	local tab,n = {},1
+	local sm = range or (s+r_ch)*2
+	for z = -sm, scale+sm do
+		local pz = z+minp.z
+		if pz%s == 0 then
+			for x = -sm, scale+sm do
+				local px = x+minp.x
+				if px%s == 0 then
+					local pr = get_random(px, pz, seed)
+					tab[n] = {x=px+pr:next(-r_ch, r_ch), y=0, z=pz+pr:next(-r_ch, r_ch)}
+					n = n+1
+				end
+			end
+		end
+	end
+
+	local tab2,n = {},1
+	for z = minp.z, maxp.z do
+		for x = minp.x, maxp.x do
+			local h = sm
+			for _,i in ipairs(tab) do
+				h = math.min(h, fct(x, i.x, z, i.z))
+			end
+			tab2[n] = {x=x, y=maxp.y-h, z=z}
+			n = n+1
+		end
+	end
+	return tab2
+end
+
+--[[
+local function dif(z1, z2)
+	return math.abs(z1-z2)
+end
+
+local function pymg(x1, x2, z1, z2)
+	return math.max(dif(x1, x2), dif(z1, z2))
+end
+
+local function romg(x1, x2, z1, z2)
+	return math.hypot(dif(x1, x2), dif(z1, z2))
+end
+
+local function py2mg(x1, x2, z1, z2)
+	return dif(x1, x2) + dif(z1, z2)
+end
+
+minetest.register_node("ac:wmg", {
+	description = "wmg",
+	tiles = {"ac_block.png"},
+	groups = {snappy=1,bendy=2,cracky=1},
+	sounds = default.node_sound_stone_defaults(),
+	on_construct = function(pos)
+		local minp = vector.chunkcorner(pos)
+		for _,p in ipairs(weird_noise(minp, pymg, 20, 8, 4)) do
+			local p2 = {x=p.x, y=p.y+1, z=p.z}
+			if p.y <= minp.y+7 then
+				local p2 = {x=p.x, y=minp.y+6, z=p.z}
+				local p3 = {x=p.x, y=p2.y+1, z=p.z}
+				if minetest.get_node(p2).name ~= "default:desert_stone" then
+					minetest.set_node(p2, {name="default:desert_stone"})
+				end
+				if minetest.get_node(p3).name ~= "default:desert_sand" then
+					minetest.set_node(p3, {name="default:desert_sand"})
+				end
+			else
+				if minetest.get_node(p).name ~= "default:desert_stone" then
+					minetest.set_node(p, {name="default:desert_stone"})
+				end
+			end
+		end
+	end,
+})]]
+
+return nether_weird_noise