Ruby Recorder dumps the result of your ruby code to a YAML file for faster tests or to compare the result between two execution.

Vi/Vim -inspired experimental GUI-oriented text editor written with Ruby and GTK.

Unit testing library with colourful, helpful error messages, small testing code footprint, good debugger integration. (Derivative work of Dfect/Detest.)

A DSL to create HTML/CSS/JS apps using Ruby.

zena is a Ruby on Rails CMS (content managment system) with a focus on usability, ease of customization and web 2.0 goodness (application like behaviour).