https://www.multitheftauto.com/

Multi Theft Auto (MTA) is a multiplayer modification for the Microsoft Windows version of Rockstar North games Grand Theft Auto III, Grand Theft Auto: Vice City and Grand Theft Auto: San Andreas that adds online multiplayer functionality. For Grand Theft Auto: San Andreas, the mod also serves as a derivative engine to Rockstar's interpretation of RenderWare.
https://en.wikipedia.org/wiki/Multi_Theft_Auto