I think it’s much quieter but perhaps it is just needing a few new HNers to discover the intoxicating subtlety? http://www.corewars.org/

There's still some occasional activity on KOTH.

http://www.koth.org/koth.html

The various hills:

    Last battle concluded at : Wed Feb 28 11:12:29 UTC 2024
    Last battle concluded at : Sun Mar 31 23:34:21 UTC 2024
    Last battle concluded at : Sun Mar 31 23:31:47 UTC 2024
    Last battle concluded at : Fri Feb 2 12:56:46 UTC 2024
    Last battle concluded at : Sun Mar 31 14:14:39 UTC 2024
    Last battle concluded at : Tue Jan 3 18:37:10 UTC 2023

'88 standard doesn't seem to be as popular as the '94 standard.

http://www.koth.org/info.html has scans of the original article.