Re: Windows?

[Judd Storrs]

On Wed, May 13, 2009 at 10:49 AM, Francesco Potorti` <address@hidden> wrote:

The reason why GPL programs cannot be linked with non-free programs is
to preserve freedom and diffuse it.  This aim is sometimes inconvenient.

To me, it looks like in this case it is not very clear whether and how
the MSVC libraries can be linked with Octave: maybe it is possible,
because the rules say that freedom is preserved to a satisfying extent,
maybe it is not, because the rules say that freedom is not preserved
enough.

The MSVC run-time libraries fall under the System Library exemption. If the GPL lacked the system library exception you would only be able to use* GPL licensed software on GPL-compatible operating systems and compilers.

It's pretty easy to agree with the FSF's rationalle if you understand that all functionality provided by the MSVC run-time libraries is fundamentally necessary for any working C++ compiler. In fact the equivaltents of these run-time libraries are included with the standard install of just about every other platform (that's why it's called a "system library" after all). The specific copyleft license used by Octave (GPL) forbids distribution of the missing sytem libraries together as a part of octave.

Microsoft's method of (not) distributing these system libraries makes it difficult to distribute GPL software for the Windows platform. I guess you could be grateful that Microsoft's current license for MSVC even allows anyone to compile and distribute GPL software at all.

--judd

*Technically by "use" I mean distribute binaries