Sun Microsystems has decided to move its desktop productivity suite, OpenOffice, from the Lesser GPLv2 to LGPLv3 to give OpenOffice increased protection against patent challenges.

"Upgrading to the LGPLv3 brings important new protections to the OpenOffice.org community, most notably through the new language regarding software patents," wrote Simon Phipps, Sun chief open source officer, in a March 6 blog.

OpenOffice is an open source alternative to Microsoft Office that is mostly compatible with the Office application suite. Microsoft complained in various forums last year that its patents cover code found in the Linux kernel and user interface and code found in other bodies of open source.

The Lesser GPL, which covers OpenOffice, is much like the original GPL but allows an individual source code library to be used in a proprietary product, without requiring the code around it to become subject to the provisions of the GPL. Among other things, the plain-vanilla GPL requires that source code be made available for free to customers. OpenOffice is included in several products, with commercial licenses governing other parts of the code.

By moving from version 2 of the LGPL to version 3, Sun is bringing new language prohibiting the use of software patents to OpenOffice.org. "The most important protection for developers comes from creating mutual patent grants. ... LGPLv3 does this," Phipps noted. In effect, a code issuer using either the plain GPL or LGPL is telling developers who adopt the code that he will not invoke any patents he may hold over that code.

OpenOffice uses Open Document Format, an XML file format standard developed by Oasis and adopted by the International Organization for Standardization. Microsoft Office uses OOXML and Microsoft is trying to get OOXML accepted as an international standard, over the objections of competitors, such as IBM and Sun, who say the document format has too many ties to proprietary technology.

This article previously identified Simon Phipps as Simon Crosby. We regret the error.