Valve have released the latest big update to the Steam client, after a good while of Beta versions bringing with it some major new features - especially on the Linux side. If you are opted into the Steam Client Beta, you will have already seen and probably used a bunch of what's new but this is for everyone sticking with the main client.
For fans of the Steam Play Proton compatibility layer, it's the big one that brings with it support for CEG DRM, making many more games playable that weren't previously. However, that currently needs you to use Proton Experimental, at least until Proton 6.3-8 rolls out (currently in testing).
Other Linux specific improvements include the "scout" and "heavy" runtimes getting better compatibility with recent Let's Encrypt TLS/SSL certificate chains, a startup crash fix was also solved for experimental versions of Mesa. The shader pre-cache system also saw improved performance and reduced disk I/O when updating Mesa caches on Linux.
There's even more for Linux! VA-API hardware encoding is now supported, with an option to turn it off if you need to. There's support for DMABUF PipeWire capture, fixes for some streaming crashes and timeouts when Linux is the host system and support for capturing up to 4K using PipeWire.
Plenty more for everyone was added including improved sync times for Steam Cloud, improved offline support for Steam Input, new Steam Deck icons in the Steam Input API and a visual update to existing icons, various fixes and improvements for connecting to the Steam servers, an update to the Chromium version used and more.