This was the position after 91.Kxb8 in the game NewRival1816 - Faile06 in a computer tournament in 2001. According to the rule, the game should have been stopped as a draw here, but this rule apparently wasn't implemented ... 493 moves is a new world record, ...
I find it hard to believe this is up-to-date, but I didn't immediately find examples to indicate otherwise (e.g.
long computer chess games didn't give anything relevant).
Question: Have there been computer-vs-computer chess games exceeding 493 moves?
For this to be meaningful, I insist that both engines were actually playing "good moves", i.e., moves that both engines thought maximized its score. Or in other words, the engines were actually playing chess, and not trying to maximize the length of the game.