Re: [gnu.org #432927] Can a Windows installer include both VC++ libs and GPLed libs?

[Michael Goffioul]

Just for the record, for those who wonder why the VC++ runtime libs
were included that way in the installer, there were actually 2 reasons:
- convenience
- possibility to install octave without admin rights

Bye,
Michael.


On Fri, May 8, 2009 at 5:09 PM, Brett Smith via RT <address@hidden> wrote:
> Hello everyone,
>
> I'm sorry for the delay in getting back to you on this; I was traveling
> when you wrote.  I think I answered a question from an Octave user about
> this a couple of days ago, so you might have already heard an initial
> response on this.  He didn't mention that Octave was the software in
> question, though, so I didn't know to include you in the discussion.
> I'm happy to help try to clear things up here.
>
>> address@hidden - Tue Apr 21 12:11:05 2009]:
>>
>> Is it a violation of the GPL (v2 and v3) to bundle the Visual C++
>> redistributable libraries and GPLed libraries in a single executable
>> installer?
>
> I do not think either version of the GNU GPL allows this kind of
> bundling.  Because these libraries are normally packaged with the
> compiler used to compile the program, ordinarily they would qualify for
> the System Library exception, which means you're exempt from providing
> their source code when you distribute the source for the program.
> However, both versions of the GNU GPL have language which prevent this
> exemption from applying to libraries that are actually distributed in
> tandem with the GPLed software.  So, the GPL expects you to include the
> source for these libraries -- and since you cannot do that, you cannot
> include them in the installer.
>
> The reason the GPL works this way is because we need to keep the System
> Library exception very narrow.  If we make it too easy for libraries to
> qualify as System Libraries, it will become feasible for companies to
> change free software and keep the changes proprietary by putting them in
> a "System Library."  The language that prevents System Libraries from
> being distributed alongside the software helps prevent this sort of abuse.
>
> To the best of my knowledge, this exact situation is the only one that
> presents problems for distributors.  As far as I'm aware, on every other
> major operating system in use today, all the libraries that would
> qualify as System Libraries come with the operating system, or are at
> least part of the standard install.  The runtime libraries for
> Microsoft's compilers are the only exception.
>
>> If that is a GPL violation, does it depend strictly on the installer
>> being an executable, or would it also apply to a .zip or .tar.gz
>> installer (e.g., a compressed archive that contains an installation
>> program and many packages to install, including the VC++ library
>> installer executable)?
>
> No.  Distributing the Octave binaries and the runtime libraries on the
> same media would be problematic, regardless of the specific medium used.
>
> I think the Windows binary distribution should simply provide users with
> instructions to obtain the libraries from Microsoft's site.  I realize
> that's inconvenient, but hopefully it's not too bad, and I think it's a
> worthwhile change to avoid any GPL trouble.
>
> If you have further questions, please feel free to contact me; I'll be
> on the lookout for those, and try to respond as quickly as possible.
>
> Best regards,
>
> --
> Brett Smith
> Licensing Compliance Engineer, Free Software Foundation
>
>