There are on-going tournaments ("hills") of which my favourite is the 94nop hill ('94 rules, without pspace).
http://www.koth.org/lcgi-bin/current.pl?hill94nop
It has been in action for approximately 25 years.
Some reference sites: https://corewar.co.uk/
And warrior library: https://users.obs.carnegiescience.edu/birk/COREWAR/corewar.h...