One of the many surprises of the Steam Deck announcement concerned SteamOS. The underlying software of SteamOS 2.0 was Debian (back when Steam Machines were a thing) but that’s been dropped for Arch Linux for version 3.0. Valve says the switch will let them use Arch’s rolling updates to keep their gaming slate up-to-date.
PC Gamer got the scoop on this. Valve designer Lawrence Yang told them: "So, Arch Linux, one of the main reasons - there's a couple - but the main reason is the rolling updates of Arch allows us to have more rapid development for SteamOS 3.0. We were making a bunch of updates and changes to specifically make sure that things work well for Steam Deck, and Arch just ended up being a better choice for them."
Debian aims for stability over up-to-date software, whereas Arch prefers rolling updates. I wouldn’t expect Valve to just push every Arch Linux update to the Deck. They’ll have their own repository for SteamOS. But with Arch, Valve will have less work to do to maintain the libraries and drivers that are being updated. They can grab up-to-date packages from Arch’s repository, ensure they don’t break anything, and then push them as part of a Steam Deck update. It’s the best of both worlds, really.
SteamOs is the most interesting part of the new device to me. I kind of know what I’m getting into with the hardware, as it’s basically a Steam Controller with a screen stuck on it (oh yeah, I went there), but I need a reason to get into Linux and stick with it. Valve’s work might get me there.