And now, with the RFacebook Rails plugin, you can have even more Facebook goodness in Rails. Besides extensions for controllers, views, models, and sessions, it even has a great debug panel for beginners that lets you see what's going on behind the scenes.
RFacebook is a production-ready library that has been deployed in a number of high-profile applications, such as Causes. The combination of extensive unit tests and a full feature set make it the most complete Facebook library for Rails.
If you are a Rails programmer, you'll want to go directly to the QuickStart. This describes how to install the Gem and the Rails Plugin. It also covers the basic features that the Rails Plugin adds to your models, views, and controllers.
In general, bugs and patches will be addressed within a week. However, you will always want to check out the Google forums to see if your problem already has a solution to it. The people there are generally friendly and quite helpful. If you do find a bug, please submit a bug report so that it can be fixed right away.
Maintaining RFacebook is not a trivial thing. There are many different ways to make a Facebook application (canvas, iframe, and external), and there are lots of obscure components of Rails that need to be modified to work properly inside Facebok. All of this needs to work seamlessly together in a single library.
If you are an experienced Rails programmer, we'd love to have you contribute to the project. Even if it's just the occasional patch, every bit counts. In particular, we need developers working on iframe applications, especially in the area of session management.