The copyright on the whole collection is 2025 - which is likely just the README or some such thing. Some of the parts are copyright 1977. For works created after 1978 copyright would last from year of first publication + 90 years, but since most of this is written in/before 1977 different laws apply. (I suspect that Activation was careful to ensure they keep their registration up to date, but there is a slight possibility this is all public domain anyway if you want to hire a lawyer to check)