Mongrel2
I'm surprised that he's doing this... after so much vitriol about the Ruby (and Rails) community and being "ripped off" with Mongrel, I would have expected him to never touch it again. Granted, it's written in C, but I'd expect it to be heavily used with Rails.<p>That said, its good that he is writing it. The more software  is written, the higher the likelihood that _something_ will be great, and when Zed Shaw's writing it, it's probably pretty good.