amber-developers: "open source" and GPL software

From: David A. Case <>
Date: Wed, 7 May 2008 15:33:20 -0700

On Wed, May 07, 2008, Ross Walker wrote:

> So could we not just redistribute SPRNG in ambertools and then have a switch
> in the main AMBER configure file that links to it in place of our current
> random number generator should the user want to do that? I.e. you need amber
> tools and amber to build a copy of amber that links to a GPL library?
> Seems this would be acceptable???

No, this would not be acceptable. See section 2b of the GPL

    b) 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.

Roughly: If your code links to a GPL routine, and you want to distribute
your code, you must distribute the entire code under the GPL.

See especially:

It might be helpful to contrast this with the "mere aggregation" clause:

   In addition, mere aggregation of another work not based on the Program
   with the Program (or with a work based on the Program) on a volume of
   a storage or distribution medium does not bring the other work under
   the scope of this License. [see also]

You can have *separate* programs that are GPL and non-GPL in the same
distribution. You cannot link GPL and non-GPL code together into a single
executable binary file.

[Note: things are different under the LGPL. This is why Volodymyr was able to
include the rmsd code from UCSF in the abmd code: the LGPL allows you to link
LPGL routines into non-GPL code.]

If this isn't clear, please visit the FAQ pages of the FSF:

Received on Sun May 11 2008 - 06:07:17 PDT
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