You see, we need computers to run them on. Today, we can get cheap motherboards for desktops, upon which we can install Linux and other Free Software. In the future, people won't use desktops as much as they use embedded devices like cell phones and web slates. So, we want to make sure that we can run new Free Software on embedded devices that already come with Free Software out of the box.
So, those two big ambitions of GPL3 are worthy of praise. But the biggest advantage of GPL3 is its legal solidity. During the creation of GPL3, literally dozens of attorneys, from the world's largest companies, reviewed every word of the license. No license anywhere has had 1/10 of the legal review that went into GPL3.
So, you can be reasonably sure that it will perform in court the way it's intended to work. Managing dozens of attorneys is difficult, but Richard Stallman was equal to the task, keeping the result in line with the ethos of Free Software.
A lot of companies like the MPL license, from the Mozilla project, better. But MPL actually only fits in the place of the in-between license; its terms aren't strong enough to provide the sharing-with-rules environment that is necessary to protect some products.
My main problem with MPL is not the license itself, but the very many licenses that have been derived from it, each with its own little differences, making the combinatorial problem of Open Source licenses significantly worse. FSF was smart to copyright their license text and maintain that there would be FSF-approved derivatives only.
It's easily possible to put together another list of three licenses that satisfies the requirements above. But this is the one that I think that most companies, and Open Source projects, should use.
I'll catch a lot of flack from people who are partisan to the BSD license, who are sticking with GPL2, who like one of the other 70, etc. But those licenses do similar things to the ones above, while being less up to date regarding how they cope with today's environment of patent and copyright infringement and all of the case law that has built up around it. When GPL 2 was written, there wasn't an Internet as we know it today, there weren't MP3 players, and the most complicated input device in most people's homes was a touch-tone phone.
If we all build our own sets of three licenses, we'll still have that combinatorial problem when we go to mix our Open Source with that of other people. We'll still have 70 different licenses, many of them in wide use. You can help to solve the problem.
Will you join me?
I said you needed 4 licenses at most, and have only discussed 3. The 4th you might consider is Affero GPL3.
This license is specifically engineered to keep Google from running away with your product without sharing their improvements to it. Well, actually, it deals with the software as a service problem. The GPL class of licenses does not require that anyone share source code until they actually distribute the software. But Google doesn't distribute software, it performs it on its own site.
So, a license had to be written to cope with the SaaS phenomenon. If you want to keep the license count down to 3, you can use Affero GPL3 in place of GPL3. The text of Affero GPL3 is very similar to that of the plain GPL3, so again, you don't really have to learn an entire new license.
So, my set includes two base licenses: Apache 2.0 and GPL3, and two derivatives of GPL3: LGPL3 and Affero GPL3. To use them, you'll have to learn two licenses, and two sets of variations on one of those licenses. All of them are compatible with each other. Suddenly, Open Source isn't as complicated as those 5,256 combinations of two of the approved 73 licenses!