The Russian Doll Pattern: Mountable apps in Rails 3 - RailsConf
One of the hottest new features in Rails 3 is the ability to embed a Rails application in another Rails application.
This allows the development of components that range from user authentication to a fully featured forum. These components can then be distributed as gems and fully integrated with another application. In fact, user private messaging could be a stand alone app, which is then mounted into a forum app, and finally mounted into your own custom app.
In this talk, Yehuda and Carl will give an in depth tutorial of this new feature. This will be done by building a CMS, creating a gem out of it, and integrating it into another app.