(limited) DVD writing support that were rejected by Schilling, who repeatedly demanded that distributions stop shipping "bastardized and defective" versions of his "legal original software". Starting with version 2.01.01a09 in May 2006, most code from cdrtools has been relicensed under the CDDL, while mkisofs remains licensed under the GPL. This change led to an ongoing disagreement about whether distribution or use of precompiled cdrtools binaries is legally possible (the GPL permits collective works, but not derivative works; and the Makefiles used to build mkisofs are CDDL licensed). The following are one-sentence summaries of the different positions: Jonathan Corbet, founder of the LWN.net news source argued that this change makes it impossible to legally distribute cdrtools binaries, because the build system used is CDDL licensed (interpreting cdrtools as derivative work of GPL and – GPL-incompatible – CDDL code) and the GPL requires "build tools and scripts also be released under the GPL". Jörg Schilling denied there was a license problem in cdrtools. In his interpretation, it consisted of independent works and thus has not mixed incompatible licenses (i.e. it is a collective work, not a derivative work). According to his interpretation, binary versions may be distributed. Fedora says the cdrtools is a "incompatible mix of the GPL and the CDDL" and Schilling's opinion is a "set of unorthodox opinions on licensing which are not shared by the FSF or Red Hat Legal" and thus cdrtools is forbidden on Fedora. Fedora's legals also proposed three solutions to solve license incompatibility (adding some sort of GPL linking exception, replace CDDL with GPL-compatible license, or dual-licensing CDDL/GPL) and consequently available to re-open discussion about including cdrtools. As is common with the GPL and other open source licenses, very little case law exists to provide guidance to users and provide a definitive answer on whether binary versions are distributable. As a result of this controversy: Debian, Red Hat, Fedora and Ubuntu dropped the versions of cdrtools with CDDL code from their distributions and switched to the Debian project created cdrkit, a fork of the last GPL-licensed cdrtools version. Jörg Schilling continued to develop his version of cdrtools under the CDDL and GPL (mkisofs) licenses until he died in 2021, whereas the cdrkit fork has received next to no updates since Cdrkit 1.1.11, which was released in 2010. Independent development efforts happen in libburnia which does not contain cdrtools source code, but includes a wrapper "cdrskin"