In 2005, the idea of synchronizing 500+ players in a world as massive as San Andreas was revolutionary.

High-speed chases across the entire state. Team Deathmatch: Chaotic turf wars in Los Santos.

The crown jewel of SA-MP. Players lived lives as cops, medics, or gang members with strict rules and complex economies.

The PAWN language allowed server owners to create entirely new games inside GTA. A World of Infinite Genres

Despite the "sync" issues (lag-shooting), it was remarkably stable.