1. RadiusA small, but powerful tag-based template language for Ruby modeled after the ones used in MovableType and TextPattern. It has tags similar to XML, but can be used to generate any form of plain text (HTML, e-mail, etc...).
2. PopupjsA prototype/lowpro based Facebook-style windowing solution
3. RubyblueA collection of themes for different text editors that mimic the colors used in the code samples on ruby-lang.org
4. TrelloappA simple unofficial wrapper application for Trello.com
5. FeedchampA simple camping application that makes it easy to aggregate a bunch of feeds into a single website.
6. ServeServe is a small Rack-based web server and rapid prototyping framework for Web applications (specifically Rails apps). Serve is meant to be a lightweight version of the Views part of the Rails MVC. This makes Serve an ideal framework for prototyping Rails applications or creating simple websites. Serve has full support for Rails-style partials and layouts.
7. Css SpinnersSimple CSS spinners and throbbers made with CSS and minimal HTML markup.
10. statusjsAllows you to display a status message when submiting a form or performing other time consuming tasks