[9] The CDDL was developed by a Sun Microsystems team (among them Solaris kernel engineer Andrew Tucker[10][11] and Claire Giordano[12]), based on the MPL version 1.1.
Cooper stated, at the 6th annual Debian conference, that the engineers who had written the Solaris kernel requested that the license of OpenSolaris be GPL-incompatible.
... the engineers who wrote Solaris ... had some biases about how it should be released, and you have to respect that.Simon Phipps (Sun's Chief Open Source Officer at the time), who had introduced Cooper as "the one who actually wrote the CDDL",[20] did not immediately comment, but later in the same video, he says, referring back to the license issue, "I actually disagree with Danese to some degree",[21] while describing the strong preference among the engineers who wrote the code for a BSD-like license, which was in conflict with Sun's preference for something copyleft, and that waiting for legal clearance to release some parts of the code under the then unreleased GNU GPL v3 would have taken several years, and would probably also have involved mass resignations from engineers (unhappy with either the delay, the GPL, or both—this is not clear from the video).
In 2006, the Debian project declared the cdrtools legally undistributable because the build system was licensed under the CDDL.
[28][29] Red Hat's attorneys have prevented cdrtools from being in Fedora or Red Hat Enterprise Linux, arguing that Schilling has an "unorthodox" view of copyright law that isn't shared by their legal counsel or the Free Software Foundation.
[30] In 2015, the CDDL to GPL compatibility question reemerged when Ubuntu announced inclusion of OpenZFS by default.
)[32] Others followed Ubuntu's conclusion, for instance James E. J. Bottomley argued there cannot be "a convincing theory of harm" developed, making it impossible to bring the case to court.
[33] Eben Moglen, co-author of the GPLv3 and founder of the SFLC, argued that while the letter of the GPL might be violated, the spirit of both licenses is unharmed, which would be the relevant aspect in court.
[35][36] On the other hand, Bradley M. Kuhn and attorney Karen M. Sandler from the Software Freedom Conservancy[37] argued that Ubuntu would violate both licenses, as a binary ZFS module would be a derivative work of the kernel.