trivial-backtrace
Trivial backtrace is a simple platform independent interface for generating a backtrace. Much of the code is borrowed from the innards of Hunchentoot.

More details can be found on its home page at Common-Lisp.net.

ASDF-install package (obsolete) http://common-lisp.net/project/trivial-backtrace/trivial-backtrace.tar.gz

Note that this functionality is now available on more platforms as part of asdf 3