Goldberg Steamemu [portable] -

Available for both Windows and Linux (including SteamOS/Steam Deck).

Play games that use Steam’s networking APIs over a local network without an internet connection. goldberg steamemu

The Goldberg Steam Emulator is a widely utilized, open-source software tool designed to emulate the Steam client API. Its primary function is to enable Steam-enabled video games (specifically those using the SteamWorks SDK) to run without the official Steam client running in the background. It is a cornerstone tool for video game preservation, LAN gaming, and software testing, allowing users to simulate Steam networking features, achievements, and save game synchronization locally. and software testing