diff --git a/ChangeLog b/ChangeLog
index 83532a58b4f8..234ec5f60936 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 # -*- coding: utf-8 -*-
 
+2008-10-25  Eric Hodel  <drbrain@segment7.net>
+
+	* lib/rubygems.rb, lib/rubygems/custom_require.rb:  Make kernel
+	methods private.  Patch #20801 by Stefan Rusterholz.  Also expose
+	our extensions to RDoc.
+
 2008-10-10  Eric Hodel  <drbrain@segment7.net>
 
 	* lib/rubygems/commands/unpack_command.rb:  Silence PATH warning.
diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 65a8d090074b..ef791e6e0462 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -43,12 +43,14 @@ module Kernel
   #
   #   GEM_SKIP=libA:libB ruby -I../libA -I../libB ./mycode.rb
 
-  def gem(gem_name, *version_requirements)
+  def gem(gem_name, *version_requirements) # :doc:
     skip_list = (ENV['GEM_SKIP'] || "").split(/:/)
     raise Gem::LoadError, "skipping #{gem_name}" if skip_list.include? gem_name
     Gem.activate(gem_name, *version_requirements)
   end
 
+  private :gem
+
 end
 
 ##
@@ -104,10 +106,10 @@ module Gem
   @ruby = nil
   @sources = []
 
-  @post_install_hooks = []
-  @post_uninstall_hooks = []
-  @pre_uninstall_hooks = []
-  @pre_install_hooks = []
+  @post_install_hooks   ||= []
+  @post_uninstall_hooks ||= []
+  @pre_uninstall_hooks  ||= []
+  @pre_install_hooks    ||= []
 
   ##
   # Activates an installed gem matching +gem+.  The gem must satisfy
diff --git a/lib/rubygems/custom_require.rb b/lib/rubygems/custom_require.rb
index 90e6b539593d..78c7872b6fc5 100755
--- a/lib/rubygems/custom_require.rb
+++ b/lib/rubygems/custom_require.rb
@@ -7,11 +7,15 @@
 require 'rubygems'
 
 module Kernel
-  alias gem_original_require require # :nodoc:
 
-  #
-  # We replace Ruby's require with our own, which is capable of
-  # loading gems on demand.
+  ##
+  # The Kernel#require from before RubyGems was loaded.
+
+  alias gem_original_require require
+
+  ##
+  # When RubyGems is required, Kernel#require is replaced with our own which
+  # is capable of loading gems on demand.
   #
   # When you call <tt>require 'x'</tt>, this is what happens:
   # * If the file can be loaded from the existing Ruby loadpath, it
@@ -22,8 +26,8 @@ module Kernel
   #
   # The normal <tt>require</tt> functionality of returning false if
   # that file has already been loaded is preserved.
-  #
-  def require(path) # :nodoc:
+
+  def require(path) # :doc:
     gem_original_require path
   rescue LoadError => load_error
     if load_error.message =~ /#{Regexp.escape path}\z/ and
@@ -34,5 +38,9 @@ def require(path) # :nodoc:
       raise load_error
     end
   end
-end  # module Kernel
+
+  private :require
+  private :gem_original_require
+
+end
 
diff --git a/lib/rubygems/defaults.rb b/lib/rubygems/defaults.rb
index 7eba0cb04913..c894bf41be34 100644
--- a/lib/rubygems/defaults.rb
+++ b/lib/rubygems/defaults.rb
@@ -1,5 +1,10 @@
 module Gem
 
+  @post_install_hooks   ||= []
+  @post_uninstall_hooks ||= []
+  @pre_uninstall_hooks  ||= []
+  @pre_install_hooks    ||= []
+
   ##
   # An Array of the default sources that come with RubyGems
 
diff --git a/util/gem_prelude.rb b/util/gem_prelude.rb
index 28bbd8372fb8..b483a65b08b3 100644
--- a/util/gem_prelude.rb
+++ b/util/gem_prelude.rb
@@ -24,14 +24,6 @@ module Gem
       :ruby_install_name => RbConfig::CONFIG["ruby_install_name"]
     }
 
-    def self.default_dir
-      if defined? RUBY_FRAMEWORK_VERSION
-        return File.join(File.dirname(ConfigMap[:sitedir]), "Gems")
-      else
-        File.join(ConfigMap[:libdir], 'ruby', 'gems', ConfigMap[:ruby_version])
-      end
-    end
-
     def self.dir
       @gem_home ||= nil
       set_home(ENV['GEM_HOME'] || default_dir) unless @gem_home
@@ -48,7 +40,22 @@ def self.path
       @gem_path
     end
 
-    # Set the Gem home directory (as reported by +dir+).
+    def self.post_install(&hook)
+      @post_install_hooks << hook
+    end
+
+    def self.post_uninstall(&hook)
+      @post_uninstall_hooks << hook
+    end
+
+    def self.pre_install(&hook)
+      @pre_install_hooks << hook
+    end
+
+    def self.pre_uninstall(&hook)
+      @pre_uninstall_hooks << hook
+    end
+
     def self.set_home(home)
       @gem_home = home
       ensure_gem_subdirectories(@gem_home)
@@ -68,8 +75,25 @@ def self.set_paths(gpaths)
     def self.ensure_gem_subdirectories(path)
     end
 
+    # Methods before this line will be removed when QuickLoader is replaced
+    # with the real RubyGems
+
     GEM_PRELUDE_METHODS = Gem.methods(false)
 
+    require 'rubygems/defaults'
+
+    begin
+      require 'rubygems/defaults/operating_system'
+    rescue LoadError
+    end
+
+    if defined?(RUBY_ENGINE) then
+      begin
+        require 'rubygems/defaults/#{RUBY_ENGINE}'
+      rescue LoadError
+      end
+    end
+
     module QuickLoader
 
       def self.load_full_rubygems_library