[Nebasuke]

I don't think this a fair interpretation of the parent comment as it's not about ownership of language. The website literally says "The next generation of ANTLR" and says "It's the successor of ANTLR4".

It's about a tool claiming to be the successor without seeming to be part of the ANTLR organisation. Are they completely different people, did the ANTLR4 owners stop writing it? There seems to be deliberately no clarification on this.

[conartist6]

I'm in the same boat with BABLR, which is designed as the successor to Babel (and named with a nod to ANTLR). I think this is just part of the benefit of free software and OSS, that someone can pick up the work and start trying to innovate without being given any kind of explicit permission. If you understand the mission and are willing and able, you can pick up the flag and start trying to run with it. You might not instantly become the recognized standard bearer for the cause, but keep pushing the flag forward people will take notice (as we are doing here).