ANTLR (ANother Tool for Language Recognition) is a powerful parser generator for reading, processing, executing, or translating structured text or binary files. It's widely used to build languages, tools, and frameworks. From a grammar, ANTLR generates a parser that can build and walk parse trees.
The Definitive ANTLR 4 Reference by Terence Parr (book @ PragProg)
ANTLR v4 is named the “Honey Badger” release after the fearless hero of the YouTube sensation The Crazy Nastyass Honey Badger. It takes whatever grammar you give it; it doesn’t give a damn!