@vanl, thanks for pointing me to summaries of the main high-level issues you’re hearing about elsewhere. Of those three—data portability and software freedom, public performance, and overall complexity—both public performance and complexity are fundamentally implementation details. However, of those details, I’d put complexity far above public performance in importance.
The “public performance” concept strikes me as both insufficient and unnecessary to achieve your goals. If you don’t need it, I’d strongly recommend you can it. You have superior tools, legal and syntactic, to achieve what you want. Refactored terms could read much easier for lawyers and non-lawyers alike. In review, they would also avoid needless, lawyer-pleasing, doctrinaire copyright conjecture.
Theoretical controversy is precisely what I feared for your draft, due to its broad-ranging implementation cleverness, which leads to an overall impression of complexity. Too-clever implementation was the original sin of GPL, and I think CAL follows where it would better not. To be clear: not just on “public performance”. The use of “quiet enjoyment” also comes to mind. But you used “quiet enjoyment” for analogy, in the data rules, while invoking “public performance” for legal effect, to invoke undefined legal behavior.
If you believe that any practical use of the software will entail exercise of other, better defined exclusive rights, deciding what “public performance” means, how that will translate across jurisdictions, and how it will apply to software, all becomes unnecessary. If you believe (or expressly require) that the terms be treated as both license and contract, you can achieve everything you need by contract and license condition. If you’re bound up in the idea that rights and rules set out in the terms have to track the boundaries of any particular IP law, especially US copyright law, I’d ask why. Isn’t that elevating esteem for the legal system’s theory of rights over the private theory of rights you mean to express by private ordering, in the terms?
Don’t get me wrong. I went to law school, and enjoy a good speculative bout of judicial will-they-or-won’t-they, on public performance or other corners of the Copyright Act not frequented by cases about software. But I don’t think the net benefit of guessing the outcome correctly serves client needs, either as CAL licensors or as CAL licensees.
Basically, if you spot some uncertainty, don’t thread it through your terms. Avoid it.