Ruby on Rails on Google App Engine

This post is a bit of a bait &#38; switch.<p>Thanks to JRuby-Rack you can run any rack compliant application framework on Google App Engine (sinatra, merb, rails).<p>However, ActiveRecord (Rails modelling component) can't actually interface with the Google App Engine datastore directly.<p>There are tools that have been built by some guys at google to wrap the Java API, but i don't see these instructions including them.

See also how to run PHP on GAE: <a href="http://www.webdigi.co.uk/blog/2009/run-php-on-the-google-app-engine/" rel="nofollow">http://www.webdigi.co.uk/blog/2009/run-php-on-the-google-app...</a>

Google App Engine accepts Java bytecode and even supports run time loading of bytecode.<p><a href="http://googleappengine.blogspot.com/2009/04/many-languages-and-in-runtime-bind-them.html" rel="nofollow">http://googleappengine.blogspot.com/2009/04/many-languages-a...</a><p>So even though there are limitations (e.g., single thread), the following languages can run on App Engine through the Java back door: PHP, Clojure, Groovy, JavaScript, Python, Ruby, Scala, Scheme, Beanshell, ...<p>Here's a wiki page with some info: <a href="http://groups.google.com/group/google-appengine-java/web/will-it-play-in-app-engine" rel="nofollow">http://groups.google.com/group/google-appengine-java/web/wil...</a><p>Also note that it's possible to run multiple languages against one datastore by using the built-in versioning system.

JavaScript on GAE: <a href="http://jack-js.appspot.com/" rel="nofollow">http://jack-js.appspot.com/</a><p>All it took was a nearly trivial servlet hooking into Rhino: <a href="http://github.com/tlrobinson/jack-servlet" rel="nofollow">http://github.com/tlrobinson/jack-servlet</a>

Note: It runs only on JRuby