What just happened? RetroArch, a frontend that brings together emulators for a wide range of classic computers and game consoles, is now available to the public through Steam. This comes after a year of beta testing, and should make using RetroArch easier.
The version of RetroArch on Steam is mostly the same as the one available on the official website or through itch.io, except for the way users download cores -- which are what let RetroArch emulate different systems. Instead of using the "Core Downloader" in RetroArch itself, users have to download them the way they would download DLC for any Steam game. RetroArch on Steam is free along with all the "DLC."
As of this writing, 10 cores are available this way. Collectively, they should let users emulate systems like the Nintendo Entertainment System, Super Nintendo, Game Boy, Atari 2600, Neo Geo, Sega Saturn, the original PlayStation, Nintendo 64, and more. Additional cores will be added in the future, but it's also possible to manually install other cores by downloading them directly from the RetroArch site and copying them into the RetroArch folder in steamapps > common > RetroArch > cores.
RetroArch has been hailed for years as a straightforward way to emulate many different classic systems through a unified interface. Downloading it through Steam should make installing and maintaining RetroArch smoother.
Steam's controller configuration settings should be a big help to RetroArch, too. While using a controller, it'll also be easier to boot up RetroArch through Steam's Big Picture mode. Starting RetroArch directly through the executable doesn't require Steam to be running.
This could prove to be a major asset to Valve's upcoming Steam Deck handheld, as RetroArch can run natively through SteamOS. A Linux installation of RetroArch would probably have worked on the Steam Deck before, but now eventual owners will be able to install and use it without leaving the Steam interface.