CLOCC
The Common Lisp Open Code Collection contains Lisp code for various applications which is:

Common Lisp
i.e. runs in ANSI Common Lisp implementations
Free Software
according to the DFSG - Debian Free Software Guidelines (e.g. licensed under GPL, LGPL, MIT-LICENSE or BSD licenses, or Public Domain)
Portable
i.e. should be portable among CL implementations with low effort, and does not require modifications to the CL implementation itself
Self-contained
i.e. does not require packages not in this repository
Ready to use
i.e. runs out of the box in the free CL implementations, except for SBCL.

Presently it includes mk-defsystem (3.6 and 4.0), CLOCC-PORT (portability code for networking and other CL extensions), and CLLIB ("a library of miscellaneous routines", including an XML parser among other things).