SteamOS, the Valve-made Linux distribution that was originally for the failed Steam Machine initiative has gradually vanished into the sidelines but it seems it won't be forever.
A while ago, we did see indications that Valve would work on SteamOS 3.0 "Clockwerk" back in 2018 but they've still been very quiet on it since apart from a few minor package updates to SteamOS 2 "Brewmaster".
Valve have been extremely active on other fronts though of course. As a quick bit of history: for Linux they put out Steam Play Proton, the ACO shader compiler for AMD, this new Steam Linux Runtime container system, the micro-compositor Gamescope and there's more with people working on all sorts under contract for Valve to improve Linux.
Still, SteamOS though, what are Valve going to do with it? Sounds like when they go back to it eventually, it might not be Debian-based. In a GitHub issue on the SteamOS page about it "languishing", another user replied with an email from Valve developer Pierre-Loup A. Griffais:
Yes, definitely lots of work still going on. Right now the focus is on core technology itself rather than distributing it, but we intend to get back to that in the future. I wouldn't expect much more movement on Debian-based Brewmaster at this point, however.
"Debian-based Brewmaster"—huh? Speculation here, but that sounds like they might be looking at a different base for whatever SteamOS 3.0 turns into.
One day then, we can clearly expect to see some movement on SteamOS once Valve get all the pieces of the Linux gaming puzzle into a state where they're truly happy with properly pushing it again. Perhaps, this will be after we finally find out what the heck Steam Cloud Gaming(#1, #2) turns out to be? Whenever we find out, we will of course let you know.
Thanks for the tag, mdeguzis.