Recently, enthusiast DryxioGTA demonstrated a modification for Grand Theft Auto: San Andreas in action. It allows the main character, Carl "CJ" Johnson, to play the previous entries of the franchise at home.
The game console in CJ's house on Grove Street can now launch GTA III and GTA Vice City:
The modder clarified that these are full ports of GTA Vice City (reVC) and GTA 3 (re3) inside GTA San Andreas:
Each game runs as a separate engine inside the San Andreas process, with its own story mode, saves, settings, and fully independent gameplay. This also means that, technically, it is possible to use mods for each game separately!