diff --git a/set.lua b/set.lua
new file mode 100644
index 0000000..13952c3
--- /dev/null
+++ b/set.lua
@@ -0,0 +1,56 @@
+local select = require "socket".select
+
+local setmetatable = setmetatable
+local insert = table.insert
+local remove = table.remove
+local ipairs = ipairs
+local error = error
+
+module "irc.set"
+
+local set = {}
+set.__index = set
+
+function new(t)
+	t.connections = {}
+	t.sockets = {}
+	return setmetatable(t, set)
+end
+
+function set:add(connection)
+	local socket = connection.socket
+	insert(self.sockets, socket)
+	
+	self.connections[socket] = connection
+	insert(self.connections, connection)
+end
+
+function set:remove(connection)
+	local socket = connection.socket
+	self.connections[socket] = nil
+	for k, s in ipairs(self.sockets) do
+		if socket == s then
+			remove(self.sockets, k)
+			remove(self.connections, k)
+			break
+		end
+	end
+end
+
+function set:select()
+	local read, write, err = select(self.sockets, nil, self.timeout)
+	
+	if read then
+		for k, socket in ipairs(read) do
+			read[k] = self.connections[socket]
+		end
+	end
+	
+	return read, err
+end
+
+-- Select - but if it times out, it returns all connections.
+function set:poll()
+	local read, err = self:select()
+	return err == "timeout" and self.connections or read
+end