antlr/antlr4 ? reverse-engineered prompt

Build me a parser generator tool that takes a grammar file and turns it into working parsers for different languages. I want it to read structured text or binary data, build parse trees, and give me a simple way to react to rules with listeners or visitors.

Please make it feel like a real developer tool, with good docs, tests, and a clean way to run the generator from the command line. It should support the main target languages this project is known for, and it should be organized so the core tool and the language runtimes stay in sync.

If anything about the current setup is unclear, check the existing docs and look up current build or usage details online if you need to. I mostly want a solid working version that someone could use to define a language or a file format and generate code from it without a lot of extra setup.