http://github.com/thatismatt/josi http://github.com/visionmedia/express http://github.com/mde/geddy
These ones haven't seen commits in over a month:
http://github.com/obt/bomberjs http://github.com/simonw/djangode
At a lower level of abstractions are the middleware layers Connect http://github.com/extjs/Connect and JSGI http://github.com/kriszyp/jsgi-node
http://news.ycombinator.com/item?id=1088699
I think I'd try Tornado first myself because of Python's error tracebacks. In my opinion they make debugging significantly easier.
Is there any other software in this space?