Static vs. Dynamic Building for GPL Open Source Software Release

[brent99]

Is there any legal issue with statically linking the QT libraries for a GPL OSS release? Or does it have to be dynamic for compliance purposes?

[jacek]

As long as the application and all libraries are on GPL there is no problem.

[brent99]

Just a follow-up comment for mass consumption....

It seems to me, based on some net reading, that you can statically link GPL program to GPL library, but you should only dynamically link proprietary program to GPL library.

Simple enough. :o Of course, in QT's case, that would be purchased copy of QT with proprietary program.

[jacek]

but you should only dynamically link proprietary program to GPL library.
No, you can't link GPL libraries with proprietary applications, but it's possible with LGPL ones. It doesn't have to be dynamic linking, but it's easier to fulfill LGPL requirements with dynamic linking.

[brent99]

If that were true, you couldn't run proprietary apps on linux, since all the linux libraries are GPL.

[wysota]

GPL excludes libraries and tools that are "distributed as part of the system" (or something similar), so you can link closed-source apps against them.

Besides, standard Linux libraries (such as glibc) are LGPL.

[jacek]

GPL excludes libraries and tools that are "distributed as part of the system" (or something similar), so you can link closed-source apps against them.
Yes, and I remember seeing an exception in one of the system headers that covered proprietary applications.