Current project: S9FES Martian Edition[1].
I wanted to get more familiar with lisp, and the easiest way I could see to get lispy in 9front[2] was with Scheme 9 from Empty Space[3]. After getting it all building and installing, I decided to start adding some minor tweaks.
Eventually, I wanted to start on a project for which I need some 9p bindings, and now I've been stuck on that for several months. It's just my fun downtime project, so rapid development isn't really a concern.
In other bits of spare time I've been working on bog[4] (actually succeeded by mire now).
Useless, but fun. Hobbies are allowed to be that way.