There's Termite (http://code.google.com/p/termite/ http://code.google.com/p/termite/), based on Gambit Scheme, which looks interesting. I haven't been able to g

There's Termite (http://code.google.com/p/termite/ http://code.google.com/p/termite/), based on Gambit Scheme, which looks interesting. I haven't been able to get Gambit to build on OpenBSD/amd64, though. There's also ConcurrentLua for Lua (http://concurrentlua.luaforge.net/ http://concurrentlua.luaforge.net/), which looks like a deliberate attempt to port Erlang's concurrency model to Lua. I hadn't worked much with Erlang when I checked that out, but it has potential. IIRC the only thing missing from Ulf Wiger's checklist is selective receive, and adding a second receive function that takes a (message->bool) function probably wouldn't be difficult. It already has asynchronous message passing, distributed computing, very cheap processes, and process monitoring.