Sun looks to GPL v3 for Java, Solaris

When it comes to open sourcing Solaris and Java, patents and politics are leading Sun toward a change of heart.

The question is which open source licence should govern the building of projects out of the company's technology crown jewels. The open source Solaris project began with a Community Development and Distribution License (CDDL), and open source Java employs version 2 of the General Public License (GPL).

Now, though, Sun likes the idea of governing both projects with the upcoming GPL version 3, chief executive Jonathan Schwartz said in a speech and an interview at the company's analyst summit in San Francisco last week.

"Will we GPL Solaris? We want to ensure we can interact with the GPL community and the Mozilla community and the BSD community," Schwartz said, referring to three major open source licences. "I don't think we've been as effective as I'd like to be in going after the GPL community, because there's an awful lot of really bright people who think that's the licence they prefer. That discussion is incredibly central to recruiting more developers around the world."

And regarding Java, Schwartz said in an interview: "We did version 2 with Java because version 3 wasn't out. When we have version 3, Java will likely go to 3."

Sun is considering the GPLv3 because it wants to appeal to developers who favor the GPL. Another factor is a patent protection expected to feature in the new version of the licence, Schwartz added.

The direction marks a new tactical approach for a company trying to find the best way to engage with members of the open source programming community, which is influential but diverse. Specifically, Sun is working with one significant party -- the Free Software Foundation, which invented the GPL and is overseeing the creation of version 3.

"Sun has now asked for our thoughts on moving the Solaris operating system to GPLv3 and what they would need to do to engage the free software developer community. Specifically, they see the advantages of creating a GNU system, utilising the kernel of Solaris," FSF Executive Director Peter Brown said in an interview.

GNU and Solaris
GNU, which stands for Gnu's Not Unix, is the FSF's attempt to create a nonproprietary clone of Unix. Right now, that effort is based on the Linux kernel. But Solaris is another possibility for the core part of the GNU operating system.

"A distribution of GNU utilising the kernel of Solaris would certainly receive at least as much support (from the FSF) as GNU with the kernel Linux," Brown said. "The fact that Sun are considering using GPLv3 would be of particular interest to us."

But the release of Solaris under GPLv3 would be unlikely to bridge a licensing divide that currently separates Solaris from Linux. Linux is covered by GPLv2, and the operating system's leader Linus Torvalds and his deputies have spurned GPLv3. Using GPLv3 for Solaris likely would preclude Linux programmers from using Solaris software, and vice-versa. That would make it difficult for Solaris to benefit from hardware support built into Linux, or for Linux to benefit from performance tools built into Solaris.

Illuminata analyst Jonathan Eunice sees "artfulness with a little bit of jujitsu" in Sun's open source licensing decisions. When the company chose the GPL for open source Java, "it prevented the mining of that asset by IBM. It's the same thing with Linux -- it prevents the Linux community from strip-mining Solaris capabilities," Eunice said.

For his part, Schwartz said patent protections expected in GPLv3 make it more appealing than the current GPLv2. It's a "licence you can use without fear of a patent attack", he said.

And he's not concerned with a repeat of the criticisms aimed at Sun when it picked the CDDL instead of the one used by Linux. "We're in a different position now. The community is a lot more comfortable with Sun now," Schwartz said.

A variety of ripple effects could stem from Sun's licensing choices. Done right, it could invigorate and broaden developer support and consequently improve the software itself. Done wrong, it could alienate those who already are involved or scare away potentially interested parties.

Sun has a strong interest in a vibrant open source community, which the company believes will lead ultimately to stronger sales of its software and hardware. Developers were the first to embrace Linux, and Sun believes the same formula can apply to its own products.

Sun may have more clout than in the past, but licensing affects where allies can be found. Apache Harmony, an open source Java project under the Apache License, is continuing in parallel with Sun's project rather than joining forces, in part because Sun chose the GPL for Java.

Dual-licence debate
It's not likely Sun would scrap the current CDDL for Solaris and move to GPLv3. Instead, the company is considering a dual licence -- a move that's possible because Sun owns the copyright to all the code in Solaris.

Stephen Harpster, director of open source software at Sun, asked OpenSolaris programmers on a mailing list last week what they thought of dual CDDL and GPLv3 licences. "We're wondering if this would increase participation. There are a lot of GPL bigots out there. If OpenSolaris were available under GPL, would there be more people willing to participate who have to date ignored us because we're CDDL only?" he asked.

Rich Teer, president of Rite Online and a member of the OpenSolaris Community Advisory Board, also cast cold water on the change. "If this is some misguided attempt to appease the GPL worshippers, I think it is doomed to failure. Most of the GPLists I've seen are staunch supporters of v2, and are unlikely to embrace v3. Given that, their attitudes towards OpenSolaris are unlikely to change," he wrote.

But not all were down on the idea. Erast Benson, one of the core developers behind a project to build an open source operating system called Nexenta, which would be based on OpenSolaris, believes a dual licence could attract more programmers.

"I bet Sun would like to increase outside contribution too. But with CDDL alone, it is just not possible in the foreseeable future," Benson said. "I believe if GPLv3 dual-licensing is done right, it will improve this situation drastically."