We recently released the 0.0.14 google-appengine gem. This release will let developers set specific versions of jruby-jars or jruby-rack by simply updating the Gemfile. We also include the necessary API jars inside appengine-apis, so now bundler does all the work. Folks looking to experiment with Rails 3, can use the App Engine Java SDK along with warbler, or just create a custom build script. App