I often write software in my spare time. Usually it's to solve a problem I'm faced with. Since I am a perfectionist, I try to make it usable for other people too.
Here is some software I've written:
Generate Ruby bindings at runtime for Gtk+ and other GObject-based libraries using the GObject Introspection Repository. This library uses Ruby-FFI to call into C, which means it works with MRI 1.8, MRI 1.9 and JRuby. Rubinius' FFI is a little behind, so is not yet supported. This project lives on GitHub, and there's an introductory blog entry.
A .MSG to mbox convertor. Convert your email files from the evil proprietary format into open standard goodness.
GIMP destriping plug-in
All my public projects can now be found on GitHub.