diff --git a/display_api b/display_api
deleted file mode 160000
index 246b7f9..0000000
--- a/display_api
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 246b7f958863e7f6b7f604b09361696226928a7b
diff --git a/display_api/API.md b/display_api/API.md
new file mode 100644
index 0000000..0d52e29
--- /dev/null
+++ b/display_api/API.md
@@ -0,0 +1,94 @@
+# Display Lib API
+This document describes Display Lib API. Display Lib allows to add a dynamic display on a node. Display Lib limits node rotations. For wallmounted, only vertical positionning is available, and for facedir, only first four position are availabel (those with default axis).
+
+## Provided methods
+### update\_entities
+**display\_lib.update\_entities(pos)**
+
+This method triggers entities update for the display node at pos. Actual entity update is made by `on_display_update` callback associated to the entity.
+
+`pos`: Position of the node
+### register\_display\_entity
+**display\_lib.register\_display\_entity(entity_name)**
+
+This is a helper to register entities used for display. 
+
+`entity_name`: Name of the entity to register.
+## Provided callback implementations
+### on_place
+**display\_lib.on\_place(itemstack, placer, pointed\_thing)**
+
+`on_place` node callback implementation. Display nodes should have this callback (avoid placement of horizontal display node).
+### on_construct
+**display\_lib.on\_construct(pos)**
+
+`on_construct` node callback implementation. Display nodes should have this callback (creates, places and updates display entities on node construction).
+### on_destruct
+**display\_lib.on_destruct(pos)**
+
+`on_destruct` node callback implementation. Display nodes should have this callback (removes display entities on node destruction). 
+### on_rotate
+**display\_lib.on\_rotate(pos, node, user, mode, new_param2)**
+
+`on_rotate` node callback implementation. Display nodes should have this callback (restricts rotations and rotates display entities associated with node).
+### on_activate
+**display\_lib.on_activate(entity, staticdata)**
+
+`On_activate` entity callback implementation for display entities. No need of this method if display entities have been registered using `register_display_entity` (callback is already set). 
+
+## Howto register a display node
+* Register display entities with `register_display_entity`
+
+* Register node with :
+  - `on_place`, `on_construct`, `on_destruct` and `on_rotate` callbacks using display_api callbacks.
+  
+  - `display_modpack_node` group. This will make this node have their entities updated as soon as the mapblock is loaded (Useful after /clearobjects).
+  
+  - a `display_entities` field in node definition containing a entity name indexed table. See below for description of each display_entities fields.
+
+### Display_entities fields
+`on_display_update` is a callback in charge of setting up entity texture. If not set, entity will have no texture and will be displayed as unknown item.
+
+`depth`, `right` and `height` : Entity position regarding to node facedir/wallmounted main axis.
+Values for these fields can be any number between -1.5 and 1.5 (default value is 0).
+Position 0,0,0 is the center of the node.
+`depth` goes from front (-0.5) to rear (0.5), `height` goes from bottom (-0.5) to top (0.5) and `right` goes from left (-0.5) to right (0.5).
+
+In order to avoid flickering text, it's better to have text a little behind node surface. A good spacing value is given by `display_api.entity_spacing` variable.
+
+### Example
+
+	display_api.register_display_entity("mymod:entity1")
+	display_api.register_display_entity("mymod:entity2")
+
+	function my_display_update1(pos, objref) 
+		objref:set_properties({ textures= {"mytexture1.png"},
+		                        visual_size = {x=1, y=1} })
+	end
+
+	function my_display_update2(pos, objref) 
+		objref:set_properties({ textures= {"mytexture2.png"},
+		                        visual_size = {x=1, y=1} })
+	end
+
+	minetest.register_node("mymod:test_display_node", {
+		...
+		paramtype2 = "facedir",
+		...
+		groups = { display_modpack_node = 1, ... },
+		...
+		display_entities = {
+			["mymod:entity1"] = { 
+				depth = 0.3,
+				on_display_update = my_display_update1 },
+			["mymod:entity1"] = { 
+				depth = 0.2, height = 0.1,
+				on_display_update = my_display_update2 },
+			},
+		...
+		on_place = display_api.on_place,
+		on_construct = display_api.on_construct,
+		on_destruct = display_api.on_destruct,
+		on_rotate = display_api.on_rotate,
+		...
+	})
diff --git a/display_api/LICENSE.txt b/display_api/LICENSE.txt
new file mode 100644
index 0000000..341c30b
--- /dev/null
+++ b/display_api/LICENSE.txt
@@ -0,0 +1,166 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
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+other than an Application or a Combined Work as defined below.
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diff --git a/display_api/README.md b/display_api/README.md
new file mode 100644
index 0000000..f51996d
--- /dev/null
+++ b/display_api/README.md
@@ -0,0 +1,14 @@
+# Display Lib
+
+This library's purpose is to ease creation of nodes with one or more displays on sides. For example, signs and clocks. Display can be dynamic and/or different for each node instance.
+
+**Limitations**: This lib uses entities to draw display. This means display has to be vertical. So display nodes rotation are limitated to "upside up" positions.
+
+**Dependancies**:default
+
+**License**: LPGL
+
+**API**: See [API.md](https://github.com/pyrollo/display_modpack/blob/master/display_api/API.md) document please.
+
+For more information, see the [forum topic](https://forum.minetest.net/viewtopic.php?t=19365) at the Minetest forums.
+
diff --git a/display_api/copyright.txt b/display_api/copyright.txt
new file mode 100644
index 0000000..02b8467
--- /dev/null
+++ b/display_api/copyright.txt
@@ -0,0 +1,6 @@
+Code by Pierre-Yves Rollo (pyrollo)
+Contributors:
+(gpcf): Compatibility with signs lib
+(Thomas--S): Fix /clearobjects bug
+(12Me21): on_place improvement and code style fixing
+
diff --git a/display_api/depends.txt b/display_api/depends.txt
new file mode 100644
index 0000000..e69de29
diff --git a/display_api/init.lua b/display_api/init.lua
new file mode 100644
index 0000000..ca7b779
--- /dev/null
+++ b/display_api/init.lua
@@ -0,0 +1,269 @@
+--[[
+    display_api mod for Minetest - Library to add dynamic display
+    capabilities to nodes
+    (c) Pierre-Yves Rollo
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--]]
+
+display_api = {}
+
+-- Prefered gap between node and entity
+-- Entity positionment is up to mods but it is a good practice to use this
+-- variable as spacing between entity and node
+display_api.entity_spacing = 0.002
+
+-- Miscelaneous values depending on wallmounted param2
+local wallmounted_values = {
+	[0]={dx=0,  dz=0,  rx=0,  rz=0,  yaw=0,          rotate=0}, -- Should never be used
+		{dx=0,  dz=0,  rx=0,  rz=0,  yaw=0,          rotate=1}, -- Should never be used
+		{dx=-1, dz=0,  rx=0,  rz=-1, yaw=-math.pi/2, rotate=5},
+		{dx=1,  dz=0,  rx=0,  rz=1,  yaw=math.pi/2,  rotate=4},
+		{dx=0,  dz=-1, rx=1,  rz=0,  yaw=0,          rotate=2},
+		{dx=0,  dz=1,  rx=-1, rz=0,  yaw=math.pi,    rotate=3}
+}
+
+-- Miscelaneous values depending on facedir param2
+local facedir_values = {
+	[0]={dx=0,  dz=-1, rx=1,  rz=0,  yaw=0,          rotate=1},
+		{dx=-1, dz=0,  rx=0,  rz=-1, yaw=-math.pi/2, rotate=2},
+		{dx=0,  dz=1,  rx=-1, rz=0,  yaw=math.pi,    rotate=3},
+		{dx=1,  dz=0,  rx=0,  rz=1,  yaw=math.pi/2,  rotate=0},
+		-- Forbiden values :
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+		{dx=0, dz=0, rx=0, rz=0, yaw=0, rotate=0},
+	}
+
+-- dx/dy = depth vector, rx/ly = right vector, yaw = yaw of entity,
+-- rotate = next facedir/wallmount on rotate
+
+local function get_values(node)
+	local ndef = minetest.registered_nodes[node.name]
+
+	if ndef then
+		if ndef.paramtype2 == "wallmounted" then
+			return wallmounted_values[node.param2]
+		end
+		if ndef.paramtype2 == "facedir" then
+			return facedir_values[node.param2]
+		end
+	end
+end
+
+--- Checks if the object is related to the given position
+local function check_entity_pos(pos, objref)
+	local real_pos = vector.round(objref:get_pos())
+	local pos_hash = objref:get_luaentity().pos
+	if pos_hash == nil then
+		return vector.equals(real_pos, vector.round(pos))
+	else
+		return vector.equals(minetest.get_position_from_hash(pos_hash), pos)
+	end
+end
+
+--- Gets the display entities attached with a node. Removes extra ones
+local function get_entities(pos)
+	local objrefs = {}
+	local ndef = minetest.registered_nodes[minetest.get_node(pos).name]
+	if ndef and ndef.display_entities then
+		for _, objref in ipairs(minetest.get_objects_inside_radius(pos, 1.5)) do
+			local entity = objref:get_luaentity()
+		    if entity and ndef.display_entities[entity.name] and check_entity_pos(pos, objref) then
+				if objrefs[entity.name] then
+				    objref:remove()
+				else
+					objrefs[entity.name] = objref
+				end
+			end
+		end
+	end
+	return objrefs
+end
+
+local function clip_pos_prop(posprop)
+	if posprop then
+		return math.max(-1.5, math.min(1.5, posprop))
+	else
+		return 0
+	end
+end
+
+--- (Create and) place display entities according to the node orientation
+local function place_entities(pos)
+	local node = minetest.get_node(pos)
+	local ndef = minetest.registered_nodes[node.name]
+	local values = get_values(node)
+	local objrefs = get_entities(pos)
+
+	if values and ndef and ndef.display_entities then
+
+		for entity_name, props in pairs(ndef.display_entities) do
+			local depth = clip_pos_prop(props.depth)
+			local right = clip_pos_prop(props.right)
+			local top = clip_pos_prop(props.top)
+			if not objrefs[entity_name] then
+				objrefs[entity_name] = minetest.add_entity(pos, entity_name)
+			end
+
+			objrefs[entity_name]:setpos({
+				x = pos.x - values.dx * depth + values.rx * right,
+				y = pos.y - top,
+				z = pos.z - values.dz * depth + values.rz * right})
+
+			objrefs[entity_name]:setyaw(values.yaw)
+		end
+	end
+	return objrefs
+end
+
+--- Call on_display_update callback of a node for one of its display entities
+local function call_node_on_display_update(pos, objref)
+	local ndef = minetest.registered_nodes[minetest.get_node(pos).name]
+	local entity = objref:get_luaentity()
+	if ndef and ndef.display_entities and entity and ndef.display_entities[entity.name] then
+		ndef.display_entities[entity.name].on_display_update(pos, objref)
+	end	
+end
+
+--- Force entity update
+function display_api.update_entities(pos)
+	local objrefs = place_entities(pos)
+	for _, objref in pairs(objrefs) do
+		objref:get_luaentity().pos = minetest.hash_node_position(pos)
+		call_node_on_display_update(pos, objref)
+	end
+end
+
+--- On_activate callback for display_api entities. Calls on_display_update callbacks
+--- of corresponding node for each entity.
+function display_api.on_activate(entity, staticdata)
+	if entity then
+		if string.sub(staticdata, 1, string.len("return")) == "return" then
+			local data = core.deserialize(staticdata)
+			if data and type(data) == "table" then
+				entity.pos = data.pos
+			end
+		end
+		entity.object:set_armor_groups({immortal=1})
+		local pos
+		if entity.pos then
+			pos = minetest.get_position_from_hash(entity.pos)
+		else
+			pos = entity.object:getpos()
+		end
+		display_api.update_entities(pos)
+	end
+end
+
+--- On_place callback for display_api items. Does nothing more than preventing item
+--- from being placed on ceiling or ground 
+function display_api.on_place(itemstack, placer, pointed_thing)
+	local ndef = itemstack:get_definition()
+	local above = pointed_thing.above
+	local under = pointed_thing.under
+	local dir = {x = under.x - above.x,
+	             y = 0,
+	             z = under.z - above.z}
+	
+	-- If item is not placed on a wall, use the player's view direction instead
+	if dir.x == 0 and dir.z == 0 then
+		dir = placer:get_look_dir()
+		dir.y = 0
+	end
+	
+	local param2
+	if ndef then
+		if ndef.paramtype2 == "wallmounted" then
+			param2 = minetest.dir_to_wallmounted(dir)
+		elseif ndef.paramtype2 == "facedir" then
+			param2 = minetest.dir_to_facedir(dir)
+		end
+	end
+	return minetest.item_place(itemstack, placer, pointed_thing, param2)
+end
+
+--- On_construct callback for display_api items. Creates entities and update them.
+function display_api.on_construct(pos)
+	display_api.update_entities(pos)
+end
+
+--- On_destruct callback for display_api items. Removes entities.
+function display_api.on_destruct(pos)
+	local objrefs = get_entities(pos)
+	
+	for _, objref in pairs(objrefs) do 
+		objref:remove()
+	end
+end
+
+-- On_rotate (screwdriver) callback for display_api items. Prevents axis rotation and reorients entities.
+function display_api.on_rotate(pos, node, user, mode, new_param2)
+	if mode ~= 1 then return false end
+
+	local values = get_values(node)
+
+	if values then
+		minetest.swap_node(pos, {name = node.name, param1 = node.param1, param2 = values.rotate})
+		place_entities(pos)
+		return true
+	else
+		return false
+	end
+end
+
+--- Creates display entity with some fields and the on_activate callback
+function display_api.register_display_entity(entity_name)
+	if not minetest.registered_entity then
+		minetest.register_entity(':'..entity_name, {
+			collisionbox = { 0, 0, 0, 0, 0, 0 },
+			visual = "upright_sprite",
+			textures = {},
+			on_activate = display_api.on_activate,
+			get_staticdata = function(self)
+				return minetest.serialize({
+					pos = self.pos,
+				})
+			end,
+		})
+	end
+end
+
+minetest.register_lbm({
+	label = "Update display_api entities",
+	name = "display_api:update_entities",
+	run_at_every_load = true,
+	nodenames = {"group:display_modpack_node", "group:display_lib_node"},
+	action = function(pos, node) display_api.update_entities(pos) end,
+})
+
+-- Compatibility
+display_lib = display_api