In the past, we, the Debian maintainers of cdrtools, had a good and mutually cooperative relationship with Jörg Schilling. He even commented on Debian bug reports, which is one of the best things an upstream maintainer can do. Naturally, there were occasionally disagreements, but this is normal.
Unfortunately Sun then developed the CDDL and Jörg Schilling released parts of recent versions of cdrtools under this license. The CDDL is incompatible with the GPL. The FSF itself says that this is the case as do people who helped draft the CDDL. One current and one former Sun employee visited the annual Debian conference in Mexico in 2006. Danese Cooper clearly stated there that the CDDL was intentionally modelled on the MPL in order to make it GPL- incompatible. For everyone who wants to hear this first-hand, we have video from that talk available.
Here is the FSF position about the CDDL. This thread contains statements on the issue made by Debian people; for more context also see the other mails in that thread. In short -- the CDDL has extra restrictions, which the GPL does not allow. Jörg has a different opinion about this and has repeatedly stated that the CDDL is not incompatible, interpreting a facial expression in the above-mentioned video, calling us liars and generally appearing unwilling to consider our concerns (he never replied to the parts where we explained why it is incompatible). As he has basically ignored what we have said, we have no choice but to fork. While the CDDL *may* be a free license, we never questioned if it is free or not, as it is not our place to decide this as the Debian cdrtools maintainers. However, having been approved by OSI doesn't mean it's ok for any usage, as Jörg unfortunately seems to assume. There are several OSI-approved licenses that are GPL-incompatible and CDDL is one of them. That is and always was our point.
For our fork we used the last GPL-licensed version of the program code and killed the incompatibly licensed build system. It is now replaced by a cmake system, and the whole source we distribute should be free of other incompatibilities, as to the best of our current knowledge.
Anyone who wants to help with this fork, particularly developers of other distributions, is welcome to join our efforts. You can contact us on IRC, server irc.oftc.net, channel #debburn, or via mail at email@example.com. Here is our svn repository.