On Wed, 23 Mar 2005, Bjoern Schiessle wrote:
On Mi, 2005-03-23 at 15:39 +0100, Laurence Finston wrote:
The following links may be of interest: http://www.gnu.org/licenses/gpl-faq.html#FSWithNFLibs http://www.gnu.org/licenses/gpl-faq.html#GPLIncompatibleLibs
This links talk about linking my GPLed program with a non-free lib. I think this point is quite clear, i as the copyright holder of the program can give a special permission to link again this non-free lib.
I interpret this differently: The copyright holder of the non-free library has given you permission to link your code to the library. This permission may be granted to everybody in the library's license.
The question is, what happens if i use also an GPLed lib in the same program were i don't have the copyright?
This is a direct quote from `http://www.gnu.org/licenses/gpl-faq.html#GPLIncompatibleLibs':
"But if you want to use parts of other GPL-covered programs by other authors in your code, you cannot authorize the exception for them. You have to get the approval of the copyright holders of those programs."
So if linking a program with two libs creates a derivated work of each other, than i can't do it until i have a permission form the copyright holder of the GPLed lib.
If A writes a library and B a program that links to A's library, I don't believe that this makes A's library a work derived from B's program. However, if I ever really needed to know this, I would ask at the FSF.
Personally, I will do my best to stay away from non-free libraries when I'm writing free software, and that's what I'd recommend to anyone else who wants to do the same. I think it would be a better use of one's time and energy to work on writing a free replacement for the non-free library.
Laurence