A new stable Steam-Client 29.04.2020 has been released for Linux veröffentlicht. It contains a lot of bugfixes:

29 April - Steam Client Update Released
A new Steam client has been released and will be automatically downloaded.

Library
Allow selection and copy of text from news popups

Steam Chat
Fixed voice chat audio issues when system is under heavy load

Steam Cloud
Fixed possible Steam client crash when playing a game using Stats and Achievements while in Offline Mode

Another free DLC for the American Truck Simulator has been released for Linux on Steam: "The Mack Anthem".

The strategy-game Total War Shogun 2 is now available for free until 01.05.2020 on Steam!

It’s a difficult time right now, so to help stave off boredom while you’re stuck at home, we’re giving away SHOGUN 2 for you to keep forever!

For Tropico 6 the Update Nueve "Guagua" and another (paid) DLC called "Spitter" have been released for Linux on Steam.

Description of the DLC:

For the American Truck Simulator the huge Update 1.37 has been released for Linux on Steam:

American Truck Simulator 1.37 Release

After much testing, feedback, fixing and fine tuning, we are excited to announce the arrival of update 1.37 for American Truck Simulator!

For the Half-Life-Remake Black Mesa the Hotfix 1.1 has been released for Linux on Steam:

Hotfix 1.1

We have tested a patch extensively on public beta and have switched it over to the mainline for everyone to use. This fix should not affect saves, but please let us know on the Steam forums or Discord if you have any issues.

Beautiful Desolation, the post-apocalyptic adventure from the developers of STASIS and CAYNE, is now available for Linux on Steam!

The Linux-version on GOG will follow soon.