Rails 2.3.5 on App Engine (TinyDS)
Recently, Takeru Sasaki was able to patch the Rails 2.3.5 calls to rubygems, and now we have it working on App Engine. He also created a datastore adapter called TinyDS. I just created an integration plugin called Rails_TinyDS that provides certain ActiveRecord method calls for Rails 2.3.5 generated scaffold.
See the DataMapper version also: gist.github.com/268192
Install the Development Environment
The gems for the development environment include a pre-release appengine-tools gem that provides a pre-release version of jruby-rack.
sudo gem install google-appengine