Ok I feel I have to step in here. That statement is patently bollocks. The syntax and semantics of a language do not denote it "being" that language - the interpreter of that syntax and semantics are what define that. It is entirely possible you could write an interpreter for the Java syntax etc that in no way produced the same output as the Java interpreter. By the same token you could adapt the Java interpreter to handle a non Java syntax.

While I agree that the syntax etc of a language play a role in defining it - they do not maketh the language in the whole.

Finally - To legally call something Java compliant you do have to get sign off from Sun. Anything else is technically not Java compliant and thus not "really" Java.