GPL likely to regain Apache compatibility

Final GPL 3 liable to be compatible with the Apache License, lowering barriers between open-source projects.
Written by Stephen Shankland, Contributor
SAN FRANCISCO--In a significant change of course, the Free Software Foundation is working to make the upcoming version 3 of the General Public License (GPL) compatible with an alternative, the Apache License.

"I think a final change we'll see for the release of GPL 3 will be that compatibility," said Free Software Foundation Executive Director Peter Brown in a panel discussion Tuesday at Sun Microsystems' JavaOne conference here. The Apache License compatibility had been removed as a result of an "11th-hour" decision before release of the third draft of GPL 3.

Compatibility among licenses permits greater sharing of code rather than separate islands of open-source software. Different licenses can impose different, sometimes conflicting requirements and restrictions. For example, the GPL requires that any changes made to software be made public as soon as software incorporating those changes is distributed, but the Apache License permits open-source code to be incorporated into proprietary software with changes hidden.

The Free Software Foundation, which originally created the GPL and is overseeing its overhaul, originally intended GPL 3 to be compatible with the Apache License, said Cliff Schmidt, vice president of legal affairs for the Apache Software Foundation. That the compatibility was removed appeared to be a result of dealing with so many issues and organizations, he said.

Now the two foundations are hammering out details of the license compatibility, Schmidt said during the panel discussion. "The two organizations are working together to make this happen," he said.

Even with license compatibility, though, constraints of the GPL mean it only will be permissible to move open-source code from Apache License projects to GPL projects, Schmidt said in an interview. That means, for example, that Sun's open-source Java project, OpenJDK, could dip from the Apache Harmony pool but not vice versa.

Ian Murdock, Sun's chief operating systems officer, said many open-source projects are separate, so the license issue doesn't crop up. "I don't think software licenses matter as much as they used to," he said.

But in some cases--such as the differing licenses covering Linux and Solaris or covering Sun's Java and the Apache Harmony equivalent--different licenses prohibit cross-pollination and sharing among similar projects.

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