The Open Source Alternative: Understanding Risks and Leveraging Opportunities

Chapter 19. LGPL Version 3.0

New Approach for LGPL

GNU Lesser General Public License Version 3.0 (LGPL3) ^[308] was released June 29, 2007, to accompany the release of GNU General Public License version 3 (GPL3). The LGPL is now an amendment to GPL3 rather than a standalone document. This is a step in the right direction, as LGPL generally was considered and treated as a variant of GPL in the past. Because LGPL3 is a variation of GPL3, the document is very short, and most of the terms applicable to LGPL code are in GPL3.

Adoption of LGPL3

The rules for availability of code under LGPL3 are the same as for GPL3. Most instantiations of the LGPL allow any code released under a particular version also to be used under any later version of the license. Now that LGPL3 has been released, many projects licensed under LGPL2 may be available under either version, but some projects will migrate to LGPL3 (or better said, LGPL3 or any later version). For those projects that do not migrate, licensees will have the option to take the code under either LGPL2 or LGPL3. However, if that licensee distributes modified code, any downstream licensees must use the version selected by the licensee.

Politics and Context

The LGPL3 drafting and comment process was largely overshadowed by the GPL3 process and therefore received relatively little attention. The Free Software Foundation (FSF) has always considered LGPL an undesirable necessity, having posted and retained on its web site an article entitled "Why You ...