Aggregation [LWN.net]

Aggregation

Posted Sep 27, 2007 19:18 UTC (Thu) by ncm (subscriber, #165)
In reply to: Aggregation by cortana
Parent article: GPL enforcement: waiting for the Monsoon

It's not so hard, if you move away from the minutiae of file and media formats.

The root question is, must the code you wrote be released under the GPL? The answer is usually simple: does some part of what it does depend on GPL code? I.e., can you run it without also running GPL code, or does some part of it depend on the GPL code to function? If the former, it's just aggregation. If the latter, it's derived.

The Linux kernel is released under a special exception: user-level code that makes system calls is not a derived work, period. The LGPL presents a similar exception: if you release your product in such a way that the user can plug in their own version of the LGPL code, your code isn't a derived work. Linux offers another special exception: a driver that depends only on explicitly exported internal kernel interfaces isn't derived.

Busybox is implementing a standard interface defined by POSIX. A program may depend on Busybox to do its work without becoming a derived work, providing it doesn't depend on non-POSIX features of Busybox.

(Not a lawyer.)

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Aggregation

Posted Oct 4, 2007 6:38 UTC (Thu) by kzm (guest, #47358) [Link]

> The root question is, must the code you wrote be released under the GPL?
> The answer is usually simple: does some part of what it does depend on GPL
> code? I.e., can you run it without also running GPL code,

So for a hardware device, you would argue that any device which runs a Linux kernel must be GPL'ed in its entirety? Including all software, firmware, and for that matter, hardware?

> The Linux kernel is released under a special exception: user-level code
> that makes system calls is not a derived work, period.

I always thought of that (and the binary modules issues) as Linus' interpretation (which at least in my jurisdiction carries considerable weight, especially when the licence is given without compensation), rather than a variation of the GPL.

At any rate, I think this interpretation is a good one: standard and available interfaces is what separates different works, messing directly with the implementation is what makes a derived work.

-k