The recent English case of BMS Business Solutions Limited v AB Agri Limited1 serves as a reminder that simply stating that a licence is "perpetual" does not necessarily mean that it cannot be terminated.
The particular facts in the case were that a software licence was originally granted on terms such that the licence terminated upon termination of a related support agreement. The parties varied the terms of the licence to make the licence perpetual, but failed to make the corresponding amendment to dis-apply the termination provisions. The High Court considered that the term "perpetual" can carry different meanings, which can vary from "never ending" to "operating without limit of time" and found that in this case that the meaning was the latter, and that there had been a grant of a licence which was of indefinite duration but which was subject to the contractual provisions governing termination of the licence.
If an English law licence is intended to be granted on a "never ending" basis, then this should be made expressly clear in the drafting. The term "perpetual and irrevocable" is commonly used to achieve this (but even with this, beware conflicting termination provisions).