This could be housed in a cgi. The page could display rules, stats of previous players, templates for competitors to build code from etc. This would give players a chance to play single player games to hone thier entry, and then could select another user housed on the page to compete against.
The player programs would send data to a form on the site which would respond with the results, this would be read back into the program to make a decision of what to do next.
Once the player is satisfied, they can post the code to the page so others can play against it, and stats can be collected on it for wins and losses.
monthly or weekly, all submission can be brought into a battle royale tournament with the winner getting a prime posting on the front page.
I think a repository of players would be handy, but the play doesn't have to be done on the host. You can download the players and the main script and run any configuration you like locally.