Valve have once again gathered all the new features and fixes from a bunch of recent Beta builds and pushed it out to everyone, this includes a bunch of nice fixes for Linux.
Steam Remote Play is one of the biggest changes (previously in-home streaming), now it's "experimentally" available outside the home too with the renaming. You should now be able to stream games from one Steam client to another, wherever they are.
On the Linux side the fixes include: a random Steam client crash when launching games, a bug where copying/moving files bigger than 2GB would fail with an I/O error, improved responsiveness to network changes, support for rumble pass-through for virtual controllers (rumble for the Steam Controller), prefer Steam Runtime's libcurl over yours which fixes "Risk of Rain" and other GameMaker titles, support for removing old Proton versions by aliasing them to more recent ones and support for developers and Valve testing specifying default Proton configuration options for games even if they're not yet white-listed.
Their Shader Pre-Caching was re-worked, to enable downloading and pre-compiling of the whole collection of Vulkan pipelines for a given game. You will likely now see them show up in the Steam client downloads area with an OpenGL/Vulkan logo below them. Valve said "Pre-compiling" will be enabled in a future Steam update. This is the feature that should, eventually, help stop stuttering in games when you first play them. They also fixed an issue with them being downloaded, even if the feature was disabled by you.
There's plenty more fixes in this update, like issues with the in-game overlay becoming "abnormally pixelated" for games using Vulkan, plenty of Steam Input updates and so on.
Full news here.
As a reminder, the Steam Library overhaul is also getting a public beta soon.