Who said that you were limited to a single Rails codebase for your application? With the advent of ActiveResource and RESTful resource-oriented controllers, it's easy to split apart a conventional Rails application at the seams between your views and models, using ActiveResource as a proxy between them.

We discuss the benefits of such an approach, including deployment flexibility, caching strategies, ready-made RESTful services, and the ability to integrate services not implemented in Rails (e.g., Atom workspaces), with examples and tips for sharing code among the Rails applications.