On Cliki.net <http://www.cliki.net/Common%20Lisp%20Utilities>, there
 is a collection of Common Lisp Utilities, things that everybody writes
 since they're not part of the official standard. There are some very
 useful things there; the only problems are that they aren't
 implemented as well as you'd like (some aren't implemented at all) and
 they aren't conveniently packaged and maintained. It takes quite a bit
 of work to carefully implement utilities for common use, commented
 and documented, with error checking placed everywhere some dumb user
 might make a mistake.