Again, I ask, what could be of such earth-shattering importance? # The only way I would install Real Player on my computer was if someone held a gun to my head and even then I would consider the fact that the afterlife might be more pleasant. “… if you want to view any kind of streaming media format on the web you either have to use WMP, RealPlayer or Quicktime.” # Porn is so ubiquitous, both in content and availability in open formats, that that is a rather ridiculous statement. It seems to me the GPL clause about derived works is overly vague and only a court could make a proper interpretation. Mozilla is able to load closed source plugins. However, there are a number of closed source Linux kernel modules. I believe there is some legal precedent for module interfaces not being copywritable (although I believe they can be patented), but I don’t know specifics and I’m certainly not a lawyer. I e-mailed the FSF for clarification on their interpretation of this matter and they never replied. I have not yet been able to find if dynamic linking constitutes a derived work, and opinions vary wildly on this issue.

As for the FSF’s interpretation (which is somewhat irrelevant compared to what a court’s interpretation would be, although it’d be nice to know what they will or won’t sue you for) they don’t provide any sort of direction as to what constitutes a derived work that I’ve been able to find.

This is a terribly sticky issue with the GPL, and at this time there is no legal precedent as to what constitutes a derived work. You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License. Here is the relevant clause from the GPL: I believe the phrase you’re looking for is “derived work”. Isnt a plugin “linking” according to the FSF?

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