Joomla License and Templates / Modules

Question

How does the GPL apply to external modules or templates installed into Joomla?

I'm a bit confused whether a module, written in PHP using the joomla API's and works only with Joomla can be commercial, or whether it must be licensed as GPL.

Also is the reason that it should not be GPL because the module was installed after Joomla and not packaged with it, or is it that the module should be licensed as GPL too since it works with Joomla and only in Joomla?

As for templates, (correct me if I'm wrong) I understand that any php in your template must be licensed as GPL, but your images, css and javascript can be licensed commercially (since they do not need Joomla to 'work').

Answer 1

This GPL discussion has been a long one in Joomla's Forums, even creating a developer centered post about this subject. An official post about changing Joomla's JED (Joomla Extension Directory) way of handling extensions is a must if you're developing Joomla Extensions.

IANAL (I'm not a Lawyer), but External Modules that are an extension (for example, inherits some Joomla classes) and wouldn't be functional without Joomla, IMO are derivative work, so they have to be GPL.

But this isn't simple. What if I create an encapsulated PHP module calles MY_MODULE, and only create some helper class in Joomla that calls MY_MODULE? MY_MODULE would exist and work outside Joomla. So, do I need to license everything as GPL or not?

These are all individual cases which need the individual examination from a lawyer.

You have to understand though that if you create a personal module and use it as a service (you have a Joomla website with a "Facebook" component you developed and users use your website), you don't have to give away your source code if you don't want to.