Styx is a scanner and parser generator designed to address some shortcomings of the traditional lex/yacc combination.
It has unique features like automatic derivation of depth grammar, production of the derivation tree including it's C interface which provides access to the abstract syntax tree, preservation of full source information and pretty printing to facilitate source-source translation, persistence to aid rapid interpreter writing.
For application in contemporary computing environments, it supports unicode, reentrancy and offers thread-safeness.
Last but not least, Styx works well under many different OSes, among them dos, windows, and serveral unixes.
It has been successfully used in many applications and is known to provide rapid compiler development. Both from our practical experience as well as from the amount of written code, the gain in development time for realistic languages versus lex/yacc is a factor of about 5-10.