diff --git a/README.md b/README.md
index 7ecfedcd..7395bdbb 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,17 @@ ruby-build provides an `rbenv-install` command that shortens this to:
 
 ### Version History
 
+#### 20110928
+
+* ruby-build now uses the `--with-gcc` configure flag on OS X Lion.
+* Added definitions for REE 1.8.7-2010.02 and 1.8.6-2009.06.
+* Modified `rbenv-install` to run `rbenv rehash` after installation.
+* Added a Ruby 1.9.3-rc1 definition.
+* Updated the JRuby defintions to install the `jruby-launcher` gem.
+* Updated the rbx-2.0.0 definition to point to the master branch.
+* Added a jruby-1.7.0-dev definition.
+* Added a Ruby 1.9.4-dev definition.
+
 #### 20110914
 
 * Added an rbx-2.0.0-dev definition for Rubinius 2.0.0 from git.
diff --git a/bin/ruby-build b/bin/ruby-build
index f8fc0c4b..690e16a6 100755
--- a/bin/ruby-build
+++ b/bin/ruby-build
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-RUBY_BUILD_VERSION="20110914"
+RUBY_BUILD_VERSION="20110928"
 
 set -E
 exec 3<&2 # preserve original stderr at fd 3
@@ -131,7 +131,7 @@ build_package_ree_installer() {
   if [[ "Darwin" = "$(uname)" ]]; then
     options="--no-tcmalloc"
   fi
-  
+
   # Work around install_useful_libraries crash with --dont-install-useful-gems
   mkdir -p "$PREFIX_PATH/lib/ruby/gems/1.8/gems"
 
@@ -147,6 +147,25 @@ build_package_rbx() {
   } >&4 2>&1
 }
 
+build_package_jruby() {
+  build_package_copy
+  cd "${PREFIX_PATH}/bin"
+  ln -fs jruby ruby
+  install_jruby_launcher
+  remove_windows_files
+}
+
+install_jruby_launcher() {
+  cd "${PREFIX_PATH}/bin"
+  { ./ruby gem install jruby-launcher
+  } >&4 2>&1
+}
+
+remove_windows_files() {
+  cd "$PREFIX_PATH"
+  rm -f bin/*.exe bin/*.dll bin/*.bat bin/jruby.sh
+}
+
 build_package_copy() {
   cp -R . "$PREFIX_PATH"
 }
diff --git a/share/ruby-build/1.9.4-dev b/share/ruby-build/1.9.4-dev
new file mode 100644
index 00000000..5db6e89a
--- /dev/null
+++ b/share/ruby-build/1.9.4-dev
@@ -0,0 +1,4 @@
+use_gcc42_on_lion
+install_package "yaml-0.1.4" "http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz"
+install_git "ruby-1.9.4-dev" "https://github.com/ruby/ruby.git" "trunk" autoconf standard
+install_package "rubygems-1.8.10" "http://production.cf.rubygems.org/rubygems/rubygems-1.8.10.tgz" ruby
diff --git a/share/ruby-build/jruby-1.6.3 b/share/ruby-build/jruby-1.6.3
index 3e899d29..b2ebdabb 100644
--- a/share/ruby-build/jruby-1.6.3
+++ b/share/ruby-build/jruby-1.6.3
@@ -1,18 +1,2 @@
-after_install_package() {
-  shim_jruby
-  remove_windows_files
-}
-
-shim_jruby() {
-  cd "${PREFIX_PATH}/bin"
-  sed -i "" 's/^#!\/bin\/bash/#!\/usr\/bin\/env bash/' jruby
-  ln -fs jruby ruby
-}
-
-remove_windows_files() {
-  cd "$PREFIX_PATH"
-  rm -f bin/*.exe bin/*.dll bin/*.bat bin/jruby.sh
-}
-
-install_package "jruby-1.6.3" "http://jruby.org.s3.amazonaws.com/downloads/1.6.3/jruby-bin-1.6.3.tar.gz" copy
+install_package "jruby-1.6.3" "http://jruby.org.s3.amazonaws.com/downloads/1.6.3/jruby-bin-1.6.3.tar.gz" jruby
 install_package "rubygems-1.6.2" "http://production.cf.rubygems.org/rubygems/rubygems-1.6.2.tgz" ruby
diff --git a/share/ruby-build/jruby-1.6.4 b/share/ruby-build/jruby-1.6.4
index 0a8b937f..a8c44bd7 100644
--- a/share/ruby-build/jruby-1.6.4
+++ b/share/ruby-build/jruby-1.6.4
@@ -1,18 +1,2 @@
-after_install_package() {
-  shim_jruby
-  remove_windows_files
-}
-
-shim_jruby() {
-  cd "${PREFIX_PATH}/bin"
-  sed -i "" 's/^#!\/bin\/bash/#!\/usr\/bin\/env bash/' jruby
-  ln -fs jruby ruby
-}
-
-remove_windows_files() {
-  cd "$PREFIX_PATH"
-  rm -f bin/*.exe bin/*.dll bin/*.bat bin/jruby.sh
-}
-
-install_package "jruby-1.6.4" "http://jruby.org.s3.amazonaws.com/downloads/1.6.4/jruby-bin-1.6.4.tar.gz" copy
+install_package "jruby-1.6.4" "http://jruby.org.s3.amazonaws.com/downloads/1.6.4/jruby-bin-1.6.4.tar.gz" jruby
 install_package "rubygems-1.6.2" "http://production.cf.rubygems.org/rubygems/rubygems-1.6.2.tgz" ruby
diff --git a/share/ruby-build/jruby-1.7.0-dev b/share/ruby-build/jruby-1.7.0-dev
new file mode 100644
index 00000000..8633b134
--- /dev/null
+++ b/share/ruby-build/jruby-1.7.0-dev
@@ -0,0 +1,2 @@
+install_package "jruby-1.7.0.dev" "http://ci.jruby.org/snapshots/jruby-bin-1.7.0.dev.tar.gz" jruby
+install_package "rubygems-1.6.2" "http://production.cf.rubygems.org/rubygems/rubygems-1.6.2.tgz" ruby
diff --git a/share/ruby-build/rbx-2.0.0-dev b/share/ruby-build/rbx-2.0.0-dev
index 47e086e4..d50cba61 100644
--- a/share/ruby-build/rbx-2.0.0-dev
+++ b/share/ruby-build/rbx-2.0.0-dev
@@ -1,2 +1,2 @@
-install_git "rubinius-2.0.0-dev" "https://github.com/rubinius/rubinius.git" "2.0.0pre" rbx
+install_git "rubinius-2.0.0-dev" "https://github.com/rubinius/rubinius.git" "master" rbx
 install_package "rubygems-1.8.10" "http://production.cf.rubygems.org/rubygems/rubygems-1.8.10.tgz" ruby
diff --git a/share/ruby-build/ree-1.8.6-20090610 b/share/ruby-build/ree-1.8.6-2009.06
similarity index 100%
rename from share/ruby-build/ree-1.8.6-20090610
rename to share/ruby-build/ree-1.8.6-2009.06