Matt didn’t insinuate that Mark’s article was about why savvy users should seek out GPL software – that was clearly Matt’s own opinion.

Mark’s article did however specifically call out the GPL (with no specific mention of any other licenses) and even spends two paragraphs detailing why and how the GPL specifically protects user’s freedom due to its insistence on variants, forks, and derivatives of the original software must bear the same license.

You are correct that an open source license can change if all of the copyright holders can come to an agreement to change the license, but given the sheer number of contributors to most large GPL code bases, it becomes a matter of impracticality: finding all of the contributors to sign off on such a change would be a monumental task and I can think of only one piece of software that did it, which is squeak (there may be others, but this is the only one I know of).

Regardless, WP is not going to change licenses anytime soon, and Matt’s personal decision tree for license choice is a matter of preference and not universal law.

Read carefully what Matt says.

First he compares the MIT license with the GPL license to explain why he prefers the latter for substantial works.

(The comparison, by the way, says something inaccurate: That an MIT license can change any day, while the GPL prevents that. That is not true: Any license can change any day as long as the copyright owners agree to change it.)

Then he goes on to cite Mark Pilgrim’s article as a cautionary tale of why “savvy” users should have the same preference.

Now go and read carefully what Mark Pilgrim writes.

Mark Pilgrim would have written the same article if WordPress was licensed under another FREE license. The four freedoms Pilgrim cares about (freedoms 0, 1, 2 and 3) are all guaranteed by ANY free license, of which, as I said, there are many: MIT/X11, Apache, BSD, GPL — the list is long. (See the link I gave above.)

Mark Pilgrim’s article is about FREE licenses and about the pitfalls of non-free licenses. It is not about which license prevents restrictive relicensing (the problem with MT is that its license was restrictive BEFORE the relicensing), it is not about the GPL, it is not about WordPress and the GPL, and it certainly is not about why the GPL license is better or worse than the MIT license, or about why “savvy” users should choose the one or the other.

Freedom 0 is a great article and, in my mind, one of the most important milestones in the history of WordPress.

But the “freedom 0” it talks about (“The freedom to run the program, for any purpose”) is not a unique feature of the GPL. It is a feature of ALL free licenses, of which there are many[1] (including the MIT license and several other well-known and widely-used licenses).

For this reason, it is misleading to present the Freedom 0 article as an argument for the GPL exclusively or explicitly. The Freedom 0 article is an argument for ALL free licenses.

[1] List of free and non-free open-source licenses according to the GNU project: http://www.gnu.org/licenses/license-list.html

Given the relative size of the project now I absolutely think going with the GPL was a smart move. The end-user freedoms afforded by the GPL have in no small part fueled the growth of the WordPress ecosystem – a platform and community that drives over 80% of my business now. The only unfortunate thing, I feel, is that we are locked into v2 – when newer versions (some that may not even be written yet) may strengthen the GPL’s position and couch its definitions to reflect modern computing conditions.

Copyright, GPL, and related issues are deeply nuanced subjects that aren’t so easily delivered as cliff notes. Each time I question my assumptions about copyright and open source licenses I learn something new about it, and about myself.

- Eric

P.S. – Thanks for the link. I’ve read it before, but its been a while. Going back to read it now.

The main difference to me is whether or not you care what happens to your code after it’s out in the world. If I’m doing small libraries or throwaway snippets I choose MIT because it has basically no restrictions and sounds cool. It can be embedded and reused and misused till the cows come home.

When I create a more substantial work, though, particularly one that targets end-users as the primary audience, I choose GPL. With MIT someone could take my code under free terms and then subject their own users to highly restrictive, freedom-limiting terms. I consider this a bad thing because it’s a net loss of freedom in the world, my work is enabling someone else to restrict their users. All the power is in the hands of the developer, they could even arbitrarily change their license from day to day. The GPL prevents that, and I consider that a more free license because the restriction on the developer that you can’t harm your users by restricting their freedom I don’t see as a negative at all because it ultimately benefits the world by increasing net freedom.

In the end, the GPL protects users, and savvy users should seek GPL-style software wherever possible. For better writing than I could do on this, and with a real-world example, check out Mark Pilgrim’s essay Freedom 0, it’s worth re-reading a few times.

http://diveintomark.org/archives/2004/05/14/freedom-0