[link|http://bistro.sourceforge.net/overview.htm|http://bistro.source....net/overview.htm]

Its a preprocessor that provides smalltalk-ish syntax and capabilities on top of Java. It generates inner classes for the closures. Its been around for at least 5 years. More of a proof of concept than a practical language - there's no debugger support or anything. But the paper is interesting.

Also, FWIW, Squeak doesn't have proper closures out of the box - it has BlockContext's instead which also don't do a good job of hanging onto local variables properly (there is a workaround you can use but you have to send the thing a message fixTemps to ask it to hang onto the temp vars).

There is a closure implementation done for Squeak, its waiting to be adopted. I think it will end up in there eventually.