diff --git a/lib/middleman.rb b/lib/middleman.rb
index bef1cadc..71dc102a 100755
--- a/lib/middleman.rb
+++ b/lib/middleman.rb
@@ -100,6 +100,52 @@ module Middleman
     
     # Organize the sitemap as a tree
     autoload :SitemapTree,         "middleman/extensions/sitemap_tree"
+    
+    class << self
+      def registered
+        @_registered ||= {}
+      end
+
+      def register(name, namespace=nil, version=nil, &block)
+        # If we've already got a matching extension that passed the 
+        # version check, bail out.
+        return if registered.has_key?(name.to_sym) && 
+        !registered[name.to_sym].is_a?(String)
+
+        if block_given?
+          version = namespace
+        end
+
+        passed_version_check = true
+        if !version.nil?
+          requirement = ::Gem::Requirement.create(version)
+          if !requirement.satisfied_by?(Middleman::GEM_VERSION)
+            passed_version_check = false
+          end
+        end
+
+        registered[name.to_sym] = if !passed_version_check
+          "== #{name} failed version check. Requested #{version}, got #{Middleman::VERSION}"
+        elsif block_given?
+          block
+        elsif namespace
+          namespace
+        end
+      end
+
+      def load(name)
+        name = name.to_sym
+        return nil unless registered.has_key?(name)
+
+        extension = registered[name]
+        if extension.is_a?(Proc)
+          extension = extension.call() || nil
+          registered[name] = extension
+        end
+
+        extension
+      end
+    end
   end
   
   # Where to look in gems for extensions to auto-register
diff --git a/lib/middleman/core_extensions/extensions.rb b/lib/middleman/core_extensions/extensions.rb
index 30bfe919..6ddd1b7c 100644
--- a/lib/middleman/core_extensions/extensions.rb
+++ b/lib/middleman/core_extensions/extensions.rb
@@ -43,55 +43,6 @@ module Middleman::CoreExtensions::Extensions
       
       app.extend ClassMethods
       app.send :include, InstanceMethods
-      
-      # Setup extension API
-      ::Middleman::Extensions.extend API
-    end
-  end
-
-  module API
-    def registered
-      @_registered ||= {}
-    end
-    
-    def register(name, namespace=nil, version=nil, &block)
-      # If we've already got a matching extension that passed the 
-      # version check, bail out.
-      return if registered.has_key?(name.to_sym) && 
-      !registered[name.to_sym].is_a?(String)
-      
-      if block_given?
-        version = namespace
-      end
-      
-      passed_version_check = true
-      if !version.nil?
-        requirement = ::Gem::Requirement.create(version)
-        if !requirement.satisfied_by?(Middleman::GEM_VERSION)
-          passed_version_check = false
-        end
-      end
-      
-      registered[name.to_sym] = if !passed_version_check
-        "== #{name} failed version check. Requested #{version}, got #{Middleman::VERSION}"
-      elsif block_given?
-        block
-      elsif namespace
-        namespace
-      end
-    end
-    
-    def load(name)
-      name = name.to_sym
-      return nil unless registered.has_key?(name)
-      
-      extension = registered[name]
-      if extension.is_a?(Proc)
-        extension = extension.call() || nil
-        registered[name] = extension
-      end
-      
-      extension
     end
   end
 
@@ -140,7 +91,7 @@ module Middleman::CoreExtensions::Extensions
     # Load features before starting server
     def initialize
       super
-    
+      
       run_hook :before_configuration
     
       # Check for and evaluate local configuration
diff --git a/lib/middleman/core_extensions/front_matter.rb b/lib/middleman/core_extensions/front_matter.rb
index 86f2cfce..6118b559 100644
--- a/lib/middleman/core_extensions/front_matter.rb
+++ b/lib/middleman/core_extensions/front_matter.rb
@@ -4,11 +4,20 @@ require "tilt"
 module Middleman::CoreExtensions::FrontMatter
   class << self
     def registered(app)
+      app.extend ClassMethods
       app.send :include, InstanceMethods
     end
     alias :included :registered
   end
   
+  module ClassMethods
+    def frontmatter_changed(matcher=nil, &block)
+      @_frontmatter_changed ||= []
+      @_frontmatter_changed << [block, matcher] if block_given?
+      @_frontmatter_changed
+    end
+  end
+  
   module InstanceMethods
     def initialize
       super
@@ -25,7 +34,7 @@ module Middleman::CoreExtensions::FrontMatter
         relative_path = path.sub(source_dir, "")
 
         data = if frontmatter.has_data?(relative_path)
-          frontmatter.data(relative_path)
+          frontmatter.data(relative_path)[0]
         else
           {}
         end
@@ -41,7 +50,18 @@ module Middleman::CoreExtensions::FrontMatter
 
         { :options => data }
       end
+    end
+    
+    def frontmatter_changed(*args, &block)
+      self.class.frontmatter_changed(*args, &block)
+    end
 
+    def frontmatter_did_change(path)
+      frontmatter_changed.each do |callback, matcher|
+        next if path.match(%r{^#{build_dir}/})
+        next if !matcher.nil? && !path.match(matcher)
+        instance_exec(path, &callback)
+      end
     end
     
     def frontmatter
@@ -78,9 +98,10 @@ module Middleman::CoreExtensions::FrontMatter
         
       if result
         file = file.sub(@app.source_dir, "")
-        @local_data[file] = result[0]
+        @local_data[file] = result
         path = File.join(@app.source_dir, file)
         @app.cache.set([:raw_template, path], result[1])
+        @app.frontmatter_did_change(path)
       end
     end
     
diff --git a/lib/middleman/sitemap/page.rb b/lib/middleman/sitemap/page.rb
index 834c2761..a5557bfd 100644
--- a/lib/middleman/sitemap/page.rb
+++ b/lib/middleman/sitemap/page.rb
@@ -71,7 +71,7 @@ module Middleman::Sitemap
     def touch
     end
     
-    def custom_render(&block)
+    def custom_renderer(&block)
       @_custom_renderer ||= nil
       @_custom_renderer = block if block_given?
       @_custom_renderer
@@ -89,7 +89,7 @@ module Middleman::Sitemap
             instance_exec(&block)
           end
         end
-      elsif !custom_render.nil?
+      elsif !custom_renderer.nil?
         params = args.dup
         params << block if block_given?
         instance_exec(*params, &custom_renderer)