JavaCC 21 is a more advanced version of the legacy JavaCC tool. The current version is the result of a huge amount of restructuring and refactoring with the following main goals:
Those who wish to know the key differences between JavaCC 21 and the legacy JavaCC project, and in particular, why they would be better off using JavaCC 21, should start here: Key Differences between JavaCC21 and Legacy JavaCC.
If you are wondering how this situation came about, you can read the history.
If you don't care about any of that and just want to get started, go here.
If you feel like you would like to get involved with this project, even if only as a vocal end-user (the squeaky wheel gets the grease!) then please consider joining our Discourse Discussion Forum.
Here is our current policy on technical support.