GetSimple License

[hameau]

Thus IMHO the plugin must be licensed under the GPL or a compatible license (one giving more rights to the user).

Yes, I understand what you say. However, note the use of "we believe" in that GNU FAQ – their point of view is not universally accepted and it is only a point of view.

Proprietary modules and the Linux kernel is another case of the same argument, but it still goes on. I can understand the distribution of a complete package (with a mix of GPL and other licences) being a violation, but to prevent plugins to GPL code from having other licences is a bit of a stretch as they don't permanently modify the original code and the effect is reversible.

Imagine a GPL CMS and a GPL plugin. This hypothetical plugin allows the CMS to have embedded YouTube video or a Google map, using public API calls. Does that change the licence of the whole installation ? Or a plugin that shows protected, non-free photographs in a gallery ? Are they not "linking dynamically or statically" to non-free code ?

Regarding Wolf's exception, I understood it to be a waiving of licence terms on a per-installation basis, but I may have got it wrong. It happens. ;-)

Edit to add : this whole argument is, of course, a lifetime's work for greater minds than mine and I tend to take a more pragmatic view than the GNU folk.