Understanding Open Source Licenses

Posted by Christopher Smith Sun, 25 Oct 2009 20:01:00 GMT

It’s quite bizarre to me the recent set of realizations, such as this one that are bouncing around the blogosphere. It’s like people aren’t familiar with the thinking behind various licenses. The GNU project’s itself is quite clear in the reasoning behind its licenses, but somehow the message has become garbled. It’s one thing that developers still learning about licensing might one day open their eyes and try to understand the licenses that they previously assigned without much thought, but I’m shocked that people would uncover these things and find them revelatory enough to justify blogging about them.

Here’s a quick summary for folks who aren’t familiar licensing that will save people a lot of navel gazing:

  • The GPL was primarily conceived as a means of protecting software freedom itself, not individual projects. Indeed, the GNU foundation acknowledges that it imposes limitations that can limit a project, but in exchange further the their cause.
  • The LGPL was primarily conceived in recognition that for certain circumstances, the GPL was unable to further the cause of freedom and was therefore would do nothing beyond harming a project itself, which in effect would hurt the cause of software freedom.
  • X11/BSD style licenses have always been the licenses that placed concerns about software/code ahead of the cause of software freedom. If that lines up with your concerns, that’s the kind of license you want.

While the defensive nature of GPL and LGPL licenses might strike people as overkill and ultimately harmful, it is helpful to keep in mind the well documented circumstances that brought about their origins. It is possible for a key contributor to a project to turn on you. One might argue that in the modern world open source is so much more successful that such events are less likely to happen, and you’d be right, but you can even find modern examples of the issues involved (contention around MySQL AB’s licensing practices comes to mind).

In short: licensing isn’t likely to change who your key contributors are, but that is far from the only issue one need contemplate when licensing.