Trestles: Replacing Rails scaffolding with something better

Ruby Linguistics: A framework for playing with English in Ruby
This library is so amazingly cool that it requires no descriptions beyond these code examples:
RaPT: A Better Plugin Manager for Rails
Geoffrey Grosenbach introduces the RaPT Plugin Manager for Rails, the answer to the problem of slow plugin installation. Installable as a gem (gem install rapt), RaPT caches the locations of different plugins so that installation is quick and easy. Future plans include developing a central plugin repository, auto-announcement of self-developed plugins, and automatic plugin upgrading. If you want the files direct, check out the Rubyforge project site for RaPT.
Write functional tests in Rails using CSS selectors

Testing for Rails Helpers
You can test your controllers, your models, and, well, most of your application, but till now there hasn't been a way to explicitly test your Rails application's helpers. Now there's a solution.. the helper_test plugin (with source and instructions).
Search Ruby files on OS X with Spotlight plugin

19 Rails Tricks Most Rails Coders Don’t Know
New to Rails 3? Check out the Ruby on Rails 3 Tutorial book and screencast.
TextMate Cheat Sheet for Ruby and Rails developers

Shattered: A nascent Ruby game development framework

Comatose, a ‘micro CMS’ plugin for Rails

MeantimeFilter: Wrap your Rails controller actions with scopes
MeantimeFilter is an interesting new plugin for Rails by Roman Le Negrate. It's a little like around_filter, but rather than using a class with 'before' and 'after' methods, it uses a single method (like the other types of filter) and passes in the method to wrap 'around' as a code block. You can then yield to this or pass it into anything you like. An example:
