ANTLREdit

ANTLR is a free parser generator.

Official site

• http://antlr.org/

Documentation

See the ANTLR book.

Third-party articles

• A nice article on using ANTLR with Xcode, although it is for the previous version of ANTLR: http://homepage.mac.com/gerard_iglesias/ANTLRWithXcode-Part-1/Text.html