Examples of modern GUI python programms

Sturla Molden sturla.molden at gmail.com
Mon Mar 31 22:16:16 CEST 2014

Metallicow <metaliobovinus at gmail.com> wrote:

> One would have to tool through the PySide agreement for their specifics,
> but as I recall it is exactly the same as Qt is, which makes sense. 

According to their web page, PySide is only LGPL. Qt is LGPL or commercial.

> Just because a library is LGPL doesn't mean the authors code has to be
> depending on the circumstances. That just means usually you have to be
> able to provide the library code(and your mods to it) used.

No, that would be MPL (Mozilla Public License). Many believe LGPL implies
the same freedom as MPL. It does not.

LGPL also means you also have to give the user a means to "relink the
program with a different version of the library". That is a less known
restriction of LGPL. Usually this is done by providing the LGPL library as
a DLL. But a DLL is actually not sufficient, in case a different version of
the library breaks the application binary interface (ABI). In case of ABI
breakage, LGPL means the user be given access to the program source code to
recompile and relink the program. 

Because of the closed nature of app bundles on iOS, the user cannot do
anything with an .so or .dylib file. Thus, the DLL solution to LGPL
infestation is not possible on iOS, even if it were sufficient.

MPL is basically a version og LGPL that has removed the requirement to make
relinkage possible. That is e.g. why a library like Eigen is released as
MPL instead of LGPL.


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