There definitely hasn't been an Open Source project similar to Pivotal Tracker and I am happy that somebody has finally taken the time to write one. I am sure, this will help many small companies like ours.

I've tried a couple of times to build a usable bug tracker (we actually use an inhouse bug tracker at our company), but this is a hard problem. It'd be great if the ruby community rallied around this and make it into the "goto bug tracker"