SteamOS

SteamOS moved to an Arch Linux base with its 3.0 release and today runs a largely immutable, read-only filesystem on the Steam Deck, with an A/B partition scheme for safe updates and a console-like 'Gaming Mode' controller-driven interface layered over a full KDE Plasma desktop that's a tap away for anyone who wants to use it like a regular PC. Its most consequential contribution to Linux gaming broadly (well beyond just SteamOS itself) is Proton, Valve's fork of Wine tuned specifically for game compatibility, which now lets a large share of Windows-only games on Steam run on any Linux distribution, not just SteamOS. While SteamOS itself officially targets Valve's own Steam Deck hardware, its Arch base and gaming-first design have directly inspired several other distributions (Bazzite, ChimeraOS, Nobara) aiming to bring the same experience to arbitrary PC hardware.