Joomla is licensed under the gpl/gnu licence, which means any 3rd party developer is obliged morally and legally to release their Joomla products under the same licence. However there are a reasonably large number of developers or software houses that do not.

Joomla.org have stated they will not litigate against these devs, but their products will not be allowed on the JED, a kind of central repository for Joomla 3rd party extensions.

I am of the opinion that anything not licensed under the gnu/gpl that is a derivative of Joomla should be treated as if it were, ie hacking the encrypted code is a moral prerogative.

(Citation needed) In France, it is not only the original developer who can sue if a derivative product is not sold under the gnu/gpl but any member of the public may do so to. Which means I could as a member of the public (as well as being a competitor developer) could sue.

In my opinion this is as it should be. Joomla are not obliged to go after licence breakers, but nor do they have the option of changing the terms of the licence, since Joomla is a derivative of mambo, a previous gnu/gpl framework.