License Conflict in slmodem-2.9.5
There is a license conflict that technically prohibits the distribution
of your software. Most of your code contains a non-copyleft but
permissive license. However, modem_at.c carries a GPL license.
This in itself is not a huge problem. Your license is substantially
similar to other licenses that the FSF says are GPL compatible (e.g. the
ZPL or the Cryptix General License).
The inclusion of the GPL licensed file triggers the requirements of
section 2b of the GPL, which requires that the entire work be GPL'd.
As I said before your license is compatible with the GPL so this on a
cursory review wouldn't be a problem.
However, you do not include source for the dsplibs.o or the amrlibs.o
file. This conflicts with section 3 of the GPL that requires the source
code be made available.
Solutions to the problem are as follows:
1) License all files under the GPL and include source for the two object
2) Change the license on modem_at.c. How you do this depends upon to
what degree you own the copyright to this code.
a) You have complete copyright to the code and remove the GPL license
replacing it with your existing license. Alternatively, you could
dual license (i.e. say you can use either your license or the GPL).
Both of these are essentially the same as your license is GPL
b) You do not have complete copyright and adapted the code from a GPL
source. In which case you are violating that persons copyright as
you are not including any copyright indicating that. I suspect
due to the lack of the copyright notice for something like that
that this isn't the case. However, if it is you would need to
get the permission to relicense the code under your license or
rewrite the code from scratch.
I believe this conflict is relatively easy to resolve. I anticipate you
can do 2a and continue on.
I'm also CC'ing debian-legal on this as they distribute your code in the
sl-modem-daemon package. The package is currently in non-free. Doing 1
would result in it being able to move to free (unless someone else sees
another problem). However, until 2 is done I'd suspect Debian is going
to have to remove the package.
Additionally, there are other files (kernel-ver.c, all the files in
patches and scripts) which do not contain any license at all. Appropriate
copyright notices should be added to them. The debian startup script
appears to have been contributed by a 3rd party so you'd need to contact
that individual to get the appropriate copyright notice. And the ALSA
patches would need to be GPL licensed in order to be applied and used.
It may be useful to include a COPYING file that applies your license to
any file that doesn't say otherwise within its contents.
If you have any questions about this please let me know. I'll be more
than happy to spend some time with you explaining the problems and
working with you to reach a resolution to this licensing problem.
Ben Reser <email@example.com>
"Conscience is the inner voice which warns us somebody may be looking."
- H.L. Mencken