ANTLR 3.2

ANTLR provides excellent support for tree construction, tree walking, translation, error recovery, and error reporting. There are currently about 5,000 ANTLR source downloads a month.

ANTLR has a sophisticated grammar development environment called ANTLRWorks, written by Jean Bovet.

There are currently about 5,000 ANTLR source downloads a month and is included on all Linux and OS X distributions. ANTLR is widely used because it's easy to understand, powerful, flexible, generates human-readable output, comes with complete source under the BSD license, is actively supported, and usually allows you to write actions in your favorite language.