arnesi
arnesi is a collection of utilities written by Marco Baringer. It includes some ASDF-extensions.

Among many other things, arnesi provides pattern matching facilities: a fare-matcher style pattern matcher and "regular" list matcher.

ASDF-install package (obsolete) http://common-lisp.net/project/bese/tarballs/arnesi_dev-latest.tar.gz

Note many parts of arnesi have been branched and improved in separate libraries:

Topic:pattern matching, continuations, accumulators, utilities, csv