Linux leader Linus Torvalds has finally found something that could convince him that the forthcoming version 3 of the General Public License is worth adopting: open-source Solaris.
"If Sun really is going to release OpenSolaris under GPL 3, that may be a good reason" to move Linux to the new license, Torvalds said in a posting to the Linux kernel mailing list on Sunday. "I don't think the GPL 3 is as good a license as (GPL) 2, but on the other hand, I'm pragmatic, and if we can avoid having two kernels with two different licenses and the friction that causes, I at least see the reason for GPLv3."
As leader of the highest-profile open-source project, Torvalds plays a key role in the protracted arrival of the GPL 3. The kernel at the heart of Linux is currently covered by GPL 2, and Torvalds and fellow kernel programmers have expressed serious reservations about new provisions in GPL 3 drafts. Torvalds moderated some of his objections with the most recent draft, though he still thinks GPL 2 is "simply the better license."
At stake in this particular element of the license debate is whether Linux and Solaris software may intermingle in a single pool of source code or whether they must remain separate, as is the case today. Commonly cited advantages for intermingling include adding Solaris' ZFS (Zettabyte File System) storage software or DTrace probing utility to Linux or adding Linux's broader hardware support to Solaris--though technical challenges still are an issue even if legal barriers are removed.
In February, members of the OpenSolaris community bristled at the possibility of releasing Solaris under the GPL. But Sun Microsystems holds the software copyright, and Chief Executive Jonathan Schwartz said in May he hopes the GPL 3 could let Sun "converge on a uniform license."
But Torvalds had plenty of cautionary disclaimers to throw cold water on those eagerly anticipating an era of Linux-Solaris cross-pollination. For one thing, he's not optimistic about Sun's declarations.
"They'll not be releasing ZFS and the other things that people are drooling about in a way that lets Linux use them on an equal footing," he offered in a "cynical prediction" posted later. "To Sun, a GPLv3-only release would actually let them look good, and still keep Linux from taking their interesting parts, and would allow them to take at least parts of Linux without giving anything back."
He admitted he could be wrong, pointing to Sun's release of Java under the GPL as an example of Sun defying his own predictions--and preferences.
"The good news is that Jonathan Schwartz actually does seem to have made a difference, and I hope to God he is really as serious about open-sourcing things as he says he is," Torvalds said. "And don't get me wrong: I think a truly open-source GPL 3 Solaris would be a really, really good thing, even if it does end up being a one-way street as far as code is concerned!"