I put up a new release/tag of IronJS on Github, called 0.1.90-preview.
It really is a preview, huge chunks of functionality (both keyword-,
operator- and standard library-wise) is still missing. However, the
API is starting to stabilize enough for those that want to start
playing around with it. You can find the tag here
http://github.com/fholm/IronJS/tree/0.1.90-preview