Enlightenment
I have been contributing to Enlightenment resp. the Enlightenment Foundation Libraries since late 2003.
The sub-projects I maintain are Euphoria, an EFL-based frontend to XMMS2 and Embrace, a graphical mail notifier.
Besides Euphoria, I also maintain EFL's Ruby bindings. The Ruby bindings for EET are managed separately.
I also wrote an alternative Edje compiler in Ruby, called Redact which probably makes a lot of edjing Rubyists happy :)