Powerful features includes LL(k) dynamic parser, Levenshtein word distance for approximative word matching, regular expressions, powerful date and number parsing functions...
One may also have a look to the ED FrameWork, which I have not yet tested, but it looks good (e.g. it has red-black trees), available under BSD license.
It is all very alpha.
storage of 2 dates, initialisation with natural language string, e.g. with "23 avr.. 3 sept 2008"
Regexuse of regular expression in NSString
StringExtensionstringBetween:and:inclusive: substring extraction
smart conversion to number, can handle natural language
date extraction, can handle natural language
nearString: approximative words matching, using Levenshtein distance
Applescript to posix path conversion
Lexer & Parser
Dynamic lexer and LL(k) parser. Tokens, defined as regex or character ranges, and parser rules are defined at run time. An abstract syntax tree (AST) is automatically generated.