“Beerware” of permissive open-source software licence terms
16 January 2024
In the context of software development, open-source software (OSS) is becoming a key concern for businesses when assessing the potential vulnerability risks and licence conflicts that could arise through its use. Legal professionals are (quite rightly) often concerned with the use of restrictive OSS and the “viral” mechanism that applies where restrictive OSS is used (see here for more information).
However, even where permissive OSS has been used, it is very important that the licence terms are carefully considered. Below are several examples of permissive OSS licences that have unusual licence terms.
JSON is an OSS tool that provides the user with a “lightweight data-interchange format”. The licence for JSON grants broad rights to the user to use the software (subject to an obligation of attribution of the author of the software and a limitation on the author’s liability) in similar terms to the permissive MIT Licence.
However, the licence also states that “the Software shall be used for Good, not Evil”. Software is defined in the licence whereas “Good” and “Evil” are not. This has the following potential implications:
- Some commentators (such as Ted Dunning of The Apache Foundation) have suggested that the obligation is merely a joke but acknowledged that a software licence is probably not the place for jokes.
- As the terms “Good” and “Evil” are not defined, there is a degree of ambiguity as to what the software can be used for to such an extent that it could be argued that the term is unenforceable (for being void for uncertainty under English law).
- Due to the terms “Good” and “Evil”, the GNU Foundation has stated that the licence does not meet the requirement of being “free” due to potential constraints it puts on users in terms of using the software.
The Beerware Licence
Poul-Henning Kamp is a software developer from Denmark and releases OSS on the terms of the following licence:
“The Beerware Licence (Revision 42):
* <[email protected]> wrote this file. As long as you retain this notice you can do whatever you want with this stuff. If we meet some day, and you think this stuff is worth it, you can buy me a beer in return.
The licence in general is extremely permissive but some concerns have been raised around the implications of if the user deems it “worth it”, the user should buy the copyright holder a beer. It is generally considered that the requirement is an option that the user can exercise rather than a mandatory obligation.
We are aware of a piece of software called JASidePanels that obliges the user to buy the copyright holder one pint of beer if the user happened to meet one of the copyright holders (the licence terms can be found here). When considering software code composition, an owner of the software would need to consider whether it was happy with this potential obligation (albeit it would likely be difficult to enforce and it is probably unlikely that you will ever bump into the copyright holders in a pub).
The Don’t Ask Me About It Licence
This permissive licence permits the user to copy and distribute the OSS as it sees fit, provided that the user does not contact the copyright holder about the OSS or in respect of any problems the user has with it.
If the OSS forms part of a software project, it could raise legal questions as to whether action can be taken against the copyright holder if legal issues are experienced in respect of the use of the OSS.
Whilst the above licence terms are most likely to have been developed by the copyright holders for their own amusement, there is a chance that the software could be used by developers and therefore form part of commercial software code base. Therefore, it is very important that companies are properly advised on the potential implications of using such software in its business.
If you have an enquiry on OSS, please do not hesitate to get in touch with your main contact or contact Jack Shreeve.
The content of this article is for general information only. It is not, and should not be taken as, legal advice. If you require any further information in relation to this article please contact the author in the first instance. Law covered as at January 2024.