I mainly develop in Ruby these days. Most of my current projects can be found on RubyForge under Copious Free Time.

amalgalite v0.14.0
Amalgalite embeds the SQLite database engine in a ruby extension
crate v0.2.2
Crate is a developer tool to help package up your application as a custom static build of the ruby interpreter plus all dependent binary extensions
heel v2.0.0
Heel is a small static web server for use when you need a quick web server for a directory
hitimes v1.0.4
Hitimes is a fast, high resolution timer library for recording performance metrics
htauth v1.0.3
HTAuth is a pure ruby replacement for the Apache support programs htdigest and htpasswd
keybox v1.2.1
Secure pasword storage.
launchy v0.3.5
Launchy is helper class for launching cross-platform applications in a fire and forget manner
rabal v0.4.0
Rabal is the Ruby Architecture for Building Applications and Libraries
ruby-libtommath v0.41.0
Ruby extension for LibTom Math
stickler v2.0.2
Stickler is a tool to organize and maintain an internal gem repository.