Peter Van Eynde pvaneynd@debian.org writes:
The file xref.lisp is not PD or GPL (unlike my greps showed) but has a rather obnoxious license that says:
You may try asking Mark Kantrowitz whether he is willing to distribute xref.lisp under a revised license. He did this for MK:DEFSYSTEM, which is now part of CLOCC (see src/defsystem-3.x/defsystem.lisp in the CLOCC distribution). If you have trouble contacting Mark, Marco Antoniotti, who took care of the MK:DEFSYSTEM license change, may be able to help.
Paolo