License in new files

[ellie timoney]

It's worth observing that the only reason we're even ABLE to consider moving away from the 4-clause BSD licence is because all copyrights from all contributors have historically been assigned to a single entity (CMU), who can then choose to transfer ownership or relicense if they desire.

If we had had a historical practice of letting individual contributors add their own copyright to individual contributions, even under the same 4-clause licence, this would require chasing approval dozens of individual copyright holders (who might not be contactable or might no longer exist), and it would probably never happen.

Whatever license we end up going with, and wherever the existing copyright assignment ends up landing (if it gets transferred), I kinda think we should maintain the same practice of requiring contributions to assign copyright to the single entity.

I'm not a lawyer, and I don't pay a lot of attention to the minutiae of open source project licensing (because I don't have to, because it's all assigned to CMU and all using the same licence!).  There's probably good examples out there of big projects that allow individual copyrights.  But the other factor to think about is -- do we have the resources to manage the administrative overhead introduced by such a scheme?  My gut feel says no: including both regular cyrus-imap and cyrus-sasl contributors, we're what, a dozen people tops?

I think it would be naive to assume we're never going to need to relicense ever again (after all, 4-clause BSD seemed like a good idea once upon a time), so let's not make things hard on our future selves.

Cheers,

ellie