segaloco via TUHS writes:
To boil that down to a specific example, once upon a
time, Sun held
a license with AT&T to use, modify, and redistribute UNIX System
V. At the present moment, Oracle is the distributor of Solaris.
If there is a piece of licensing paperwork sitting in a filing
cabinet at Oracle somewhere, who would that paperwork say is the
original licensor of the product? Would that even matter in this
year of 2025?
At some point Sun bought out their license from AT&T. My guess is
it was pre-Solaris 9, as that buyout was what let them start offering
up Solaris 9 source code on an experimental basis, and then fully
unleashing it with the Solaris 10 release.
As Warren mentions, others might have done the same, but I
have no knowledge of any deals other than Sun's.
--lyndon