An example Rails 3.2 app for a web startup prelaunch site.
Fancy is a dynamic, object-oriented programming language inspired by Smalltalk, Ruby, Io and Erlang that runs on the Rubinius VM.
OpenGL accelerated 2D game framework for Ruby
Reputation system Rails engine.
What ActiveModel left out
manager and generator of simple, searchable, command line cheatsheets
Interrogate attempts to bring Scheme-like class predication to Ruby.
Adds support for creating state machines for attributes on any Ruby class
Warbler chirpily constructs .war files of your Ruby applications.
Open-source Dropbox using Ruby and Git
a branch of Mochi Media's excellent HTTP library -- their canonical source can be found at http://code.google.com/p/mochiweb/
Fully-featured ruby parser generation using ANTLR version 3