I guess that what you miss about rails is the MVC architectural layout, but that's not specific to RoR and you can use it wherever you want, even in the webapp

I guess that what you miss about rails is the MVC architectural layout, but that's not specific to RoR and you can use it wherever you want, even in the webapp microframework for google app engine: have a file or module for models, another for controllers and another for views and get them together in a main module; you can also use django (I've used django 1.1 in gae with no problem) or use Jruby on appengine (there's a whole project for that: http://code.google.com/p/appengine-jruby/ http://code.google.com/p/appengine-jruby/) to run ruby on rails, padrino or sinatra, if you really miss ruby. I've also run ruby projects on app-engine (in sinatra, which is the coolest microframework out there, IMO) and it's been easy, I actually felt it easier to set up that a django project, as it was hack free.