Licensing: choose Open Source licenses GPL-compatible

David Wheeler, who I frequently mention talking about Commercial open source, just released a revised version of his “Make Your Open Source Software GPL-compatible. Or else”, a paper arguing that FLOSS developers should use existing widely-used license GPL compatible.cliff fall - mind your step!

I asked him what was new, and as he suggested me to check the latest version against the last known to the WaybackMachine, then the diff utility did the rest. The result confirms just what he anticipated me by email:

I know I added info about Wine. I’m sorry I didn’t mention them earlier, because they’re a really interesting case. They switched from non-GPL to X license, which helped. They later switched to LGPL, which increased their number of contributions. Both REALLY interesting.

In the list of important FLOSS projects gone under (painful) changes to make themselves GPL-compatible he just added:

As noted in Wine history, Wine’s, “history of licensing has sparked many debates.” The WINE project originally had the BSD-old license, a GPL-incompatible license; this incompatibility with the GPL drove the developers to switch to the GPL-compatible X11 license in January 2000. Many developers expressed concern about appropriation of the code by commercial entities, so in March 2002 the developers agreed to switch Wine to the LGPL license. The “ReWind” project was created for those who wanted an X11-licensed codebase, but most developers decided to focus their efforts on synchronizing with the LGPL’ed Wine, and the vast majority of development and new features appear there first. The Wine project reports that shortly after changing the license to the LGPL, development began to pick up at a greater pace (more patches began to appear, the leader Alexandre made more CVS commits, and more applications were reported to work).

I didn’t know that the Wine project experienced such a positive trend because of license change. Knowing that Alexandre Julliard contributed most of his code back to the Wine project as CodeWeavers’s CTO, I’m wondering if others were contributing while employed by other proprietary software firms.
Getting back to the original topic, I agree with David’s hint, choosing GPL-compatible license allow you to take advantage of lots of programs and libraries licensed under GPL.

If you want to be sure your license is GPL-compatible just use the GPL, or choose from the FSF’s list of licenses compatible with the GPL: determining GPL compatibility can be a difficult task.

Take the European Union’s license, time and effort has been spent to create such draft, and to let people use it make me wonder about the propaeudetic value of Esperanto.

Even when talking about Linux Kernel, despite as clearly wrote Linus Torvalds:

In short, apart from the very early code in 1991 and early -92 (versions 0.01 through 0.12), Linux has been licensed with _only_ the GPLv2 license file, and normally no mention of “v2 or later” in the actual sources.

A recent and clear analysis showed as it is inaccurate:

License # Bytes % Bytes
GPL 2 or above 60,637,907 39%
GPL 2 only 32,215,150 21%
GPL, Ver unspecified 19,773,264 13%
Other 43,762,840 28%
All Combined 156,389,161 100%

When choosing your next license, mind your step!

Technorati Tags: Open Source, GPL