It seems like a cross between CoffeeScript and JavaScript, leaning towards the JS side. I haven't tried it, but some of the new features it adds seem interesting (like the ability to use "if var isn't value { }"). I like that it translates 1:1, so that you don't have to hunt down strange errors in code that you didn't organize. However, the automatic semicolon insertion a) is already in JS, in some cases, and b) could get obnoxious.