That's something I've also been wondering lately, since the Kepler and Orbit projects haven't seen activity for ages (at least according to their webpages).<p>I found this Sinatra clone for Lua called Mercury (<a href="http://github.com/nrk/mercury" rel="nofollow">http://github.com/nrk/mercury</a>), but it lacks documentation and does not seem to be very mature at the moment.