(Why? Is this obsolete, or what? Old contents (restored from v7 of this page) follow. - DavidLindes)
XPTEST is a test framework based on Extreme Programming. These ideas were first expressed in a test framework for Smalltalk illustrated in the paper Simple Smalltalk Testing: With Frameworks by Kent Beck.
The source code of XPTEST is distributed under a DFSG-compatible license. The project page (dead link) provides instructions for accessing the CVS source tree. A Debian package exists which uses common-lisp-controller, and may be apt-get'ed from the repository mentioned on the Debian page.
See also Test framework comparison.
There is also a Debian package.