Karl Berry has been going over the libcdio code (http://www.gnu.org/software/libcdio) to change it from GPL V2 to V3. In the process he remarked The BSD license used these days (no advertising clause) is compatible with the GPL (both 2 and 3). So you can incorporate BSD-licensed code in libcdio, there is no legal problem. The particular file in question is http://cvsweb.netbsd.se/cgi-bin/bsdweb.cgi/pkgsrc/misc/libcdio/files/_cdio_netbsd.c?rev=1.3;content-type=text%2Fx-cvsweb-markup which he maintains is compatible with GPL and mentions http://www.gnu.org/licenses/license-list.html . Basically, he says one keeps the license of the original code. So if he's correct and there is no *legal* problem, there is of course there's the question of whether folks would take offence and/or if it would be desireable. I've sent email to drochner at the netbsd org address asking for his view since his email is listed on the existing 0.76 source code. Thoughts and comments?