Had an interesting conversation today with Wim about copyright and software. We are currently working on integrating some RTSP patches into GStreamer and it turns out these patches contain some code originating in Xine which means we need to get a relicense on the code to the LGPL or replace the GPL parts.

Part of the problem is that people in the free software community tend to be rather sloppy with copyright statements when copying code around. So when people take code from a GPL project to put into another GPL project they often don’t copy all the needed copyright headers over as well, and also a lot of people when making significant changes don’t add their names to the copyright header of the file.

On top of that there are issues like the hard to grasp definition of what exactly constitutes a copyrightable contribution and the general problems with programming languages not being very expressive by nature, meaning that there isn’t that many (non stupid) ways of doing something.

Neither of us being a lawyer probably doesn’t help either :)

Anyway all of this makes it a quite extensive task to a) identify all (potential) copyright holders on a specific piece of code. b) track all these people down. c) get their permission to relicense d) if anyone says no, identify exactly what is their contribution and figure how that can be removed. Figuring out what to do when things are not easy to rewrite in any intelligent way, as a rewrite would basically look like the original and so on.

In terms of rewrites being identical to the original copyright law addresses this with rules saying that only the expressive elements of code is copyrightable, but its not easy for a layman to have a clear feeling on what that translates into in terms of a specific piece of code. In many cases you can never really know, even with a good lawyer to help you, before a judge gives final verdict on it. And having a judge give final verdict is what you probably want to avoid in the first place as that process costs a lot of time and money.

What is certain is that it do seem clear to me that copyright law was not made with gigantic collaborative efforts, which open source software is an example of, in mind. (ok, I am not expecting any awards for spotting the obvious :)