From the ‘License Renewal’ files:
The Mozilla Public License is one of the most influential software licenses in recent memory. In many respects, it is the basis for alot of modern idea about open source, as opposed to just Free Software and the GPL.
This week, the Mozilla Public License 2.0 was officially released – and to be honest, I was caught a little off guard. I’ve known that work was in progress since at least 2008. In 2010, Mozilla Chief Mitchell Baker let us know that the new MPL 2.0 would remove references to Netscape in the license.
Even with that three years of work, there just didn’t seem to be the same level of …controversy..that existed in say the GPL 3 revision process.
That’s probably a good thing too.
MPL 2.0 is an evolution, not a revolution. It’s about cleaning up and accounting for 10+ years of changes in the tech world. It’s about finally coming to terms with the reality that MPL should be compatible with GPL.
Mozilla’s own What’s New page does a great job of explaining the differences between MPL 1.1 and the new 2.0 license, but the explanation of the GPL language is my favorite bit.
Providing an explicit mechanism by which MPL and GPL code can be distributed together has several significant benefits:
It allows elimination of the common dual and tri-license approach, which reduces license proliferation, since (for compatibility and proliferation purposes) each dual-license and tri-license is a separate license.
Along with Apache compatibility, it creates a series of upwards-compatible free software licenses covering much of the world’s free and open source software.
It helps protect the original licensor’s ability to reintegrate modifications made downstream, by requiring that the initial distribution of changes occurs under both licenses and not just the GPL.
I never really understood the whole tri-license approach and now, I don’t really have too since compatibility is built in moving forward. While the MPL is used for and by Mozilla, it’s important to remember that others have used the license too.
The ‘funny’ thing to me is that a couple years ago, the most common type of license that new open source startups liked to use was a MPL plus attribution type of license. That has now fallen out favor (though there is the CPL which is the same thing). I see alot of GPL and alot of Apache licenses but not nearly all that many new MPL licensed projects.
Time will tell whether this newer, kinder, gentler MPL 2.0 will be widely adopted beyond Mozilla. I personally think that ship has sailed though, but hey it’s not as if Mozilla doesn’t have a pile of its own interesting projects and effort that will now benefit from the MPL 2.0.