Take a look at snap (http://snapframework.com/ http://snapframework.com/) as well. I'm working on a small project with it, and I'm really enjoying the type syst

Take a look at snap (http://snapframework.com/ http://snapframework.com/) as well. I'm working on a small project with it, and I'm really enjoying the type system after getting over the initial hump. Also, it has great concurrency performance characteristics (http://snapframework.com/blog/2010/11/17/snap-0.3-benchmarks http://snapframework.com/blog/2010/11/17/snap-0.3-benchmarks), though that wasn't much of a factor in me deciding to try it.