Rngom is an open-source java library for parsing relax ng grammars.

in particular, rngom can:
* parse the xml syntax
* parse the compact syntax
* check all the semantic restrictions as specified in the specification
* parse relax ng into application-defined data structures
* build a default data structure based around the binarized simple syntax
or another data structure that preserves more of the parsed information
* parse foreign elements/attributes in a schema
* parse comments in a schema