Check it out - JavaCC has been relicensed under BSD! And it's official, too; from the dev list:
So now you can redistribute JavaCC itself - the code, the example grammars, all that. This comes up on the user's list regularly, and it's nice to have a clear answer now. And here's the official post to debian-legal.
JavaCC seems to be picking up steam lately; more grammars are being released, the user's mailing list activity is picking up, and some new features and bugfixes are getting done. On my TODO list is getting JavaCC to generate JJTree code that use JDK 1.5 features - take a look at the code generated by JJTreeState and you can see where generics and autoboxing would do it some good. Good times ahead!
Of course, I'm a bit biased since I'm halfway through writing a JavaCC book. But still!