: Version 1.39 is a popular "legacy" version because it was a major transition point for sound engine parameters, requiring specific updates for older sound mods. Official Download and Version Management For those looking to download or revert to version 1.39:
While there isn't one definitive "piece" of software labeled this way, the "ETS2 1.39" query typically refers to a specific era of Euro Truck Simulator 2 Ets2 1.39 Download Google Drive