Apache, GPL License Compatibility Back On Track


The Free Software Foundation's goal to make the GNU General Public License (GPL) compatible with the Apache License isn't dead, as the most recent GPL 3 draft indicated.

Representatives of the FSF and the Apache Software Foundation said Tuesday that they expect to iron out the "11th hour" legal problem that created incompatibility in the latest and near-final GPL revision draft, released in March.

"I think the final change we'll see before the GPL 3 release will be that compatibility," FSF Executive Director Peter Brown said during a panel discussion on open-source topics at the JavaOne conference in San Francisco.

Cliff Schmidt, Apache's vice president for legal affairs, also offered a vote of confidence that that the two organizations will work through their differences and achieve license compatibility. "I think so, but I've also been known to be an optimist," he said.

Apache incompatibility was the biggest surprise in the most recent GPL 3 draft, the latest iteration of a revamping process that has lasted more than a year and is expected to conclude this summer. The GPL is the most widely used open-source license, and its incompatibility with the Apache License -- a widely respected, business-friendly license -- has long been a headache for open-source developers.

Becoming compatible with Apache was one goal of the GPL redrafting process, which is orchestrating the first changes in more than 15 years to the landmark open-source license.

That compatibility seemed in reach, but in the latest GPL 3 version -- the third draft posted for public comment -- a complex patent-termination clause interpretation problem appeared to scuttle it.

"We regret that we will not achieve compatibility [with Apache] despite what we had previously promised," GPL 3's drafters wrote in a companion document outlining changes in the new version.

Apache and the FSF have been talking ever since, and a detente seems likely, Schmidt said. He cast the dispute as an argument over an inadvertent technicality, rather than a fundamental, ideological rift.

"I think this is just what happens when you have so many different issues. Something fell through the cracks," he said. "The two organizations are working together to make this happen, and I'm very confident that it will."

GPL 3 is now on track to be finalized in August. Its adoption will be a major milestone in the open-source industry and will force developers of GPL-licensed software to make choices about migrating to the new license or contributing to a potential schism between version 2 and version 3 software. Sun's Java is currently licensed "version 2 only."

Sun isn't taking an official position on migrating until GPL 3 is finalized. "It's a little too early to comment on how it's going to land," Sun software head Rich Green said.

Still, Sun is sending signals that it likes what it sees. Sun Chief Open-Source Officer Simon Phipps has praised the redrafting process as thoughtful and transparent. Sun has been a close participant in the GPL revision and a strong evangelist for the license.

Asked Tuesday about why Sun chose the GPL to cover Java, rather than the custom Common Development and Distribution License (CDDL) it used for its earlier Solaris release, Green answered, "The real question is, why didn't we chose GPL for Solaris?"

Though Sun offered no comment on its Solaris licensing plans, executives have long hinted that GPL licensing is under consideration.

"We're very, very, very focused right now on the GPL community," Sun CEO Jonathan Schwartz said in a discussion of Sun's decision to open-source Java. "We've seen an overwhelming embrace."