Broca
Broca (named after Broca's Area, the region in the brain which concentrates language understanding functions) is an Objective-C library for creating and dealing with PEG (Parsing Expression Grammar) parsers. It is inspired by Language.js (http://github.com/tolmasky/language/), and implements most of it's characteristics, especially that no parse ever fails, instead generating error objects meant for further user treatment.
Features
To be written, as soon as the EBNF Parser is ready. In the meanwhile, you can read about general PEG features on the wikipedia page here: http://en.wikipedia.org/wiki/Parsing_expression_grammar