Mozilla Public License

In computing, the Mozilla Public License is an open source and free software license. Version 1.0 was developed by Mitchell Baker when she worked as a lawyer at Netscape Communications Corporation and version 1.1 at the Mozilla Foundation.

Its main use has as the controlling license for the Mozilla web browser and related software. It has been adapted by others as a license for their software, most notably Sun Microsystems, as the Common Development and Distribution License for OpenSolaris (the open source version of Solaris 10).

The license is regarded as a weak copyleft. Specifically, source files copied or changed under the MPL must stay under the MPL; however, they may be combined in a program with proprietary files. Thus, a proprietary version may be released of an MPLed open source program — for example, Netscape Navigator versions 6 and 7, which are proprietary versions of corresponding releases of the Mozilla Suite.

The Mozilla Suite itself, and Mozilla Firefox, are being relicensed under the GNU General Public License (GPL) and GNU Lesser General Public License (LGPL) as well as the MPL. The relicensing effort is waiting on permission to relicense a last few remaining files, else to rewrite them.

Comments from Free Software Foundation

This is a free software license which is not a strong copyleft; unlike the X11 license, it has some complex restrictions that make it incompatible with the GNU GPL. That is, a module covered by the GPL and a module covered by the MPL cannot legally be linked together. We urge you not to use the MPL for this reason.

However, MPL 1.1 has a provision (section 13) that allows a program (or parts of it) to offer a choice of another license as well. If part of a program allows the GNU GPL as an alternate choice, or any other GPL-compatible license as an alternate choice, that part of the program has a GPL-compatible license.

References

• Mozilla Public License (Free Software Foundation)
• The Time 100: Mitchell Baker: The "Lizard Wrangler" (Marc Andreesen, Time, 18 April 2005)

External links

• Mozilla Public License, version 1.1 (Mozilla.org)
• MPL FAQ (Mozilla.org)
• Promiscuous Source (GPL vs. MPL) (David Wallace Croft)