ANTLR can be used to define data formats instead of using XML /JSON/YAML etc
What is ANTLR?
ANTLR, ANother Tool for Language Recognition, is a language tool that provides a framework for constructing recognizers, interpreters, compilers, and translators from grammatical descriptions containing actions in a variety of target languages. 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. 
