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).

I found this Sinatra clone for Lua called Mercury (http://github.com/nrk/mercury), but it lacks documentation and does not seem to be very mature at the moment.

LuaForge's ftp server is broken since the big LuaForge crash a few months ago, so those pages are badly out of date. Browse http://github.com/keplerproject for more recent information.

Yeah, I've poked around a bit as well, but didn't find anything that seemed like it was getting traction.

I was excited when I heard that mod_lua was going to be included with Apache by default [1] ... but I haven't really heard anything since then.

[1] http://news.ycombinator.com/item?id=452396