diff --git a/lib/oga.rb b/lib/oga.rb
index 657670f..b9eb488 100644
--- a/lib/oga.rb
+++ b/lib/oga.rb
@@ -6,6 +6,9 @@ require_relative 'oga/xml/lexer'
 require_relative 'oga/xml/parser'
 require_relative 'oga/xml/node'
 require_relative 'oga/xml/element'
+require_relative 'oga/xml/comment'
+require_relative 'oga/xml/text'
+require_relative 'oga/xml/document'
 require_relative 'oga/xml/builder'
 
 require_relative 'oga/html/parser'
diff --git a/lib/oga/xml/builder.rb b/lib/oga/xml/builder.rb
index f497196..45a024f 100644
--- a/lib/oga/xml/builder.rb
+++ b/lib/oga/xml/builder.rb
@@ -9,19 +9,68 @@ module Oga
     class Builder < ::AST::Processor
       attr_reader :ast
 
-      ##
-      # @param [Oga::AST::Node] ast
-      #
-      def initialize(ast)
-        @ast = ast
+      def on_document(node)
+        document = Document.new
+        document.children = process_all(node)
+
+        document.children.each do |child|
+          child.parent = document
+        end
+
+        return document
+      end
+
+      def on_comment(node)
+        return Comment.new(:text => node.children[0])
       end
 
       def on_element(node)
+        ns, name, attr, *children = *node
 
+        if attr
+          attr = process(attr)
+        end
+
+        if children
+          children = process_all(children)
+        end
+
+        element = Element.new(
+          :name       => name,
+          :namespace  => ns,
+          :attributes => attr,
+          :children   => children
+        )
+
+        element.children.each_with_index do |child, index|
+          if index > 0
+            child.previous = element.children[index - 1]
+          end
+
+          if index + 1 <= element.children.length
+            child.next = element.children[index + 1]
+          end
+
+          child.parent = element
+        end
+
+        return element
       end
 
       def on_text(node)
+        return Text.new(:text => node.children[0])
+      end
 
+      alias_method :on_cdata, :on_text
+
+      def on_attributes(node)
+        pairs = process_all(node)
+
+        return Hash[pairs]
+      end
+
+      def on_attribute(node)
+        return *node
       end
     end # Builder
   end # XML
diff --git a/lib/oga/xml/comment.rb b/lib/oga/xml/comment.rb
new file mode 100644
index 0000000..eeb0eae
--- /dev/null
+++ b/lib/oga/xml/comment.rb
@@ -0,0 +1,13 @@
+module Oga
+  module XML
+    ##
+    #
+    class Comment < Node
+      attr_accessor :text
+
+      def to_xml
+        return "<!--#{text}-->"
+      end
+    end # Comment
+  end # XML
+end # Oga
diff --git a/lib/oga/xml/document.rb b/lib/oga/xml/document.rb
new file mode 100644
index 0000000..e587831
--- /dev/null
+++ b/lib/oga/xml/document.rb
@@ -0,0 +1,14 @@
+module Oga
+  module XML
+    ##
+    # Class description
+    #
+    class Document < Node
+      attr_accessor :dtd, :xml_version, :encoding
+
+      def to_xml
+        return children.map(&:to_xml).join('')
+      end
+    end # Document
+  end # XML
+end # Oga
diff --git a/lib/oga/xml/element.rb b/lib/oga/xml/element.rb
index bb55eb5..4e057b8 100644
--- a/lib/oga/xml/element.rb
+++ b/lib/oga/xml/element.rb
@@ -5,14 +5,30 @@ module Oga
     # attributes and child nodes.
     #
     class Element < Node
-      ##
-      # @param [String] name The name of the element
-      # @see Oga::XML::Node#initialize
-      #
-      def initialize(name, options = {})
-        super(options)
+      attr_accessor :name, :namespace, :attributes
 
-        @name = name
+      def after_initialize
+        @attributes ||= {}
+      end
+
+      def attribute(name)
+        return attributes[name]
+      end
+
+      alias_method :attr, :attribute
+
+      def to_xml
+        ns    = namespace ? "#{namespace}:" : ''
+        body  = children.map(&:to_xml).join('')
+        attrs = ''
+
+        attributes.each do |key, value|
+          attrs << "#{key}=#{value.inspect}"
+        end
+
+        attrs = " #{attrs}" unless attrs.empty?
+
+        return "<#{ns}#{name}#{attrs}>#{body}</#{name}>"
       end
     end # Element
   end # XML
diff --git a/lib/oga/xml/node.rb b/lib/oga/xml/node.rb
index 8c087cf..3eca9ef 100644
--- a/lib/oga/xml/node.rb
+++ b/lib/oga/xml/node.rb
@@ -1,20 +1,20 @@
 module Oga
   module XML
     ##
-    # @!attribute [r] parent
+    # @!attribute [rw] parent
     #  @return [Oga::XML::Node]
     #
-    # @!attribute [r] children
+    # @!attribute [rw] children
     #  @return [Array<Oga::XML::Node>]
     #
-    # @!attribute [r] next
+    # @!attribute [rw] next
     #  @return [Oga::XML::NOde]
     #
-    # @!attribute [r] previous
+    # @!attribute [rw] previous
     #  @return [Oga::XML::Node]
     #
     class Node
-      attr_reader :parent, :children, :next, :previous
+      attr_accessor :parent, :children, :next, :previous
 
       ##
       # @param [Hash] options
@@ -30,6 +30,10 @@ module Oga
         options.each do |key, value|
           instance_variable_set("@#{key}", value) if respond_to?(key)
         end
+
+        @children ||= []
+
+        after_initialize if respond_to?(:after_initialize)
       end
     end # Element
   end # XML
diff --git a/lib/oga/xml/text.rb b/lib/oga/xml/text.rb
new file mode 100644
index 0000000..dc0d211
--- /dev/null
+++ b/lib/oga/xml/text.rb
@@ -0,0 +1,13 @@
+module Oga
+  module XML
+    ##
+    #
+    class Text < Node
+      attr_accessor :text
+
+      def to_xml
+        return text.to_s
+      end
+    end # Text
+  end # XML
+end # Oga