diff --git a/railties/bin/gen b/railties/bin/gen
index 9f105d2e196cadd79fee5df3a1c7d78850795181..809e75acb5c45f70eab7a45647a0f94dd9686ed2 100755
--- a/railties/bin/gen
+++ b/railties/bin/gen
@@ -10,33 +10,9 @@ end
 require File.dirname(__FILE__) + '/../lib/generators'
 
 if ARGV.size == 0
-  rails = Rails::Generators.builtin.map do |group, name|
-    name if group == "rails"
-  end
-  rails.compact!
-  rails.sort!
-
-  others = Rails::Generators.builtin.map do |group, name|
-    "#{group}:#{name}" unless rails.include?(name)
-  end.compact
-  others.sort!
-
-  puts "Please select a generator."
-  puts "Builtin: #{rails.join(', ')}."
-  puts "Others: #{others.join(', ')}." unless others.empty?
-
+  Rails::Generators.help
   exit
 end
 
-Rails::Generators.builtin.each do |group, name|
-  require "generators/#{group}/#{name}/#{name}_generator"
-end
-
 name = ARGV.shift
-
-if klass = Rails::Generators.find_by_namespace(name, "rails")
-  ARGV << "--help" if klass.arguments.any? { |a| a.required? } && ARGV.empty?
-  klass.start
-else
-  puts "Could not find generator #{name}."
-end
+Rails::Generators.invoke name, ARGV, :invoke
diff --git a/railties/lib/commands/destroy.rb b/railties/lib/commands/destroy.rb
index f4b81d65117f049c4110a4092e30463c17ffd167..204477b7388607d4cc87fb65f694e4dc6ac57352 100644
--- a/railties/lib/commands/destroy.rb
+++ b/railties/lib/commands/destroy.rb
@@ -1,6 +1,10 @@
 require "#{RAILS_ROOT}/config/environment"
-require 'rails_generator'
-require 'rails_generator/scripts/destroy'
+require 'generators'
 
-ARGV.shift if ['--help', '-h'].include?(ARGV[0])
-Rails::Generator::Scripts::Destroy.new.run(ARGV)
+if ARGV.size == 0
+  Rails::Generators.help
+  exit
+end
+
+name = ARGV.shift
+Rails::Generators.invoke name, ARGV, :revoke
diff --git a/railties/lib/commands/generate.rb b/railties/lib/commands/generate.rb
index 3d3db3d8565eed337aedb2da522153f160d399af..7d133a179e9d08da0cd70369d50f3aeb4c914463 100755
--- a/railties/lib/commands/generate.rb
+++ b/railties/lib/commands/generate.rb
@@ -1,6 +1,10 @@
 require "#{RAILS_ROOT}/config/environment"
-require 'rails_generator'
-require 'rails_generator/scripts/generate'
+require 'generators'
 
-ARGV.shift if ['--help', '-h'].include?(ARGV[0])
-Rails::Generator::Scripts::Generate.new.run(ARGV)
+if ARGV.size == 0
+  Rails::Generators.help
+  exit
+end
+
+name = ARGV.shift
+Rails::Generators.invoke name, ARGV, :invoke
diff --git a/railties/lib/commands/update.rb b/railties/lib/commands/update.rb
index 83ef833300ad561c1dd7eef68796307dcc481e0d..0c14355f248c503477c166725c8754f9179b8f6f 100644
--- a/railties/lib/commands/update.rb
+++ b/railties/lib/commands/update.rb
@@ -1,4 +1,10 @@
 require "#{RAILS_ROOT}/config/environment"
-require 'rails_generator'
-require 'rails_generator/scripts/update'
-Rails::Generator::Scripts::Update.new.run(ARGV)
+require 'generators'
+
+if ARGV.size == 0
+  Rails::Generators.help
+  exit
+end
+
+name = ARGV.shift
+Rails::Generators.invoke name, ARGV, :skip
diff --git a/railties/lib/generators.rb b/railties/lib/generators.rb
index fd7d3c958045099a2e05587c5436bb9735dd3d66..8814f6e8003d09c36101f669ef5f260172f286a0 100644
--- a/railties/lib/generators.rb
+++ b/railties/lib/generators.rb
@@ -25,7 +25,7 @@ def self.builtin
     #
     # ==== Examples
     #
-    #   lookup_by_namespace :webrat, :rails, :integration
+    #   find_by_namespace :webrat, :rails, :integration
     #
     # Will search for the following generators:
     #
@@ -36,7 +36,7 @@ def self.builtin
     #
     # Finally, it deals with one kind of shortcut:
     #
-    #   lookup_by_namespace "test_unit:model"
+    #   find_by_namespace "test_unit:model"
     #
     # It will search for generators at:
     #
@@ -51,12 +51,46 @@ def self.find_by_namespace(name, base=nil, context=nil)
       attempts << name
 
       attempts.each do |namespace|
-        klass, task = Thor::Util.find_by_namespace(namespace)
+        klass = Thor::Util.find_by_namespace(namespace)
         return klass if klass
       end
 
       nil
     end
+
+    # Show help message with available generators.
+    #
+    def self.help
+      rails = Rails::Generators.builtin.map do |group, name|
+        name if group == "rails"
+      end
+      rails.compact!
+      rails.sort!
+
+      puts "Please select a generator."
+      puts "Builtin: #{rails.join(', ')}."
+
+      # TODO Show others after lookup is implemented
+      # puts "Others: #{others.join(', ')}."
+    end
+
+    # Receives a namespace, arguments and the behavior to invoke the generator.
+    # It's used as the default entry point for generate, destroy and update
+    # commands.
+    #
+    def self.invoke(namespace, args=ARGV, behavior=:invoke)
+      # Load everything right now ...
+      builtin.each do |group, name|
+        require "generators/#{group}/#{name}/#{name}_generator"
+      end
+
+      if klass = find_by_namespace(namespace, "rails")
+        args << "--help" if klass.arguments.any? { |a| a.required? } && args.empty?
+        klass.start args, :behavior => behavior
+      else
+        puts "Could not find generator #{namespace}."
+      end
+    end
   end
 end