Features marked with [DEV] will appear with the next official release of ANTLR. Feel free to try them out by getting the current development version from FishEye.

I'd appreciate if you try it out and send me feedback, but don't be surprised by bugs or strange behaviour.
Tree parsers are currently not supported, but token parsers should work (with and without AST generation).
I suggest to run ANTLRWorks from a console (java -jar antlrworks.jar) and keep and eye on the output. If the parser sends garbage over the socket, ANTLRWorks stops the debugger, but doesn't show an explicit message to the user that something went wrong.
Also watch the console which runs the parser as a bug may cause an exception which also doesn't trigger a user notification in ANTLRWorks.