[sane-devel] Please give me some help to solve the license issues in using sane

[m. allan noah]

On 6/6/08, Alessandro Zummo <azummo-lists at towertech.it> wrote:
> On Fri, 6 Jun 2008 16:36:39 +0200
>
> Alessandro Zummo <azummo-lists at towertech.it> wrote:
>
>
> > On Fri, 6 Jun 2008 10:26:04 -0400
>  > "m. allan noah" <kitno455 at gmail.com> wrote:
>  >
>  > >
>  > > no, the GPL is all about derivative works and combining code, it makes
>  > > no difference the direction:
>  >
>  >  You are probably right, the closest entry in the faq that describes this situation
>  >  seems to be http://www.gnu.org/licenses/gpl-faq.html#GPLAndPlugins
>
>
>
>  but also relevant are:
>
>   http://www.gnu.org/licenses/gpl-faq.html#FSWithNFLibs
>   http://www.gnu.org/licenses/gpl-faq.html#GPLIncompatibleLibs
>
>   so if I am the author of the GPLed software it seems that I'm able
>   to give an exception and link against a non GPL lib.
>
>  <cite>
>  If you want your program to link against a library not covered by the system
>  library exception, you need to provide permission to do that.
>  </cite>
>

yes- this seems reasonable, however, this 'program' cannot be derived
from existing GPL'd software that does not already have this added
permission, because that would change the original program's license
without permission of the authors.

so, is our answer to Mengqiang that there are only four choices?

1. you can write an entirely free backend, and use code from SANE.

2. you can write a partly free backend, that runs the closed parts as
a separate process, and use code from SANE in the free part, provided
that the interface to the closed parts is simple and well documented.

3. you can write a partly free backend, that dynamically links to the
closed parts, provided that you place a license exception in the free
part allowing said linking. you cannot use any code from SANE, other
than sane.h and the sane specification, in either part.

4. you can write an entirely closed backend. you cannot use any code
from SANE, other than sane.h and the sane specification.

Note that Mengqiang's original suggestion of having a combined library
(or even collection of libs) that has some SANE code in it is
specifically not allowed?

allan
-- 
"The truth is an offense, but not a sin"