I wrote a transcompiler (just like CoffeeScript) to Java that supports multiple inheritance. It is very buggy and limited and does not allow many flexible formatting options, but it is still there and I would be more than happy if you checked it out or made a branch from it to improve it. I will probably add more features and fix many of the bugs, but for now, it at least works.
https://github.com/Philoprogrammer/Java-With-Multiple-Inheritance
