If you have previously opted into public beta, you already have this. For all others, here is the list of changes:
Update 173456 contains a number of general fixes in the game, as well as some that are specific to the Linux version.
- IMPORTANT FOR LINUX: Most of the weird performance problems in previous builds were caused by performance throttling (aka power saving) features on various CPUs not correctly identifying that the game is running and continually jittering between low and high performance modes (several times per second sometimes!). This build adds a workaround for this which should hopefully prevent the symptoms from being so extreme. It is not perfect however, as there might still be a few percents of performance to squeeze out. The recommended solution is to turn off such features in BIOS for Linux machines. They can be found in BIOS under names such as SpeedStep, Cool'N'Quiet, C1E, PowerNow!, Power Saving, CPU Throttling, Dynamic Frequency Scaling, or something else - depending on your BIOS.
- Added a script that offers to automatically install libpci.3 on linux if it is missing. - Fixed graphics corruption under OpenGL if game is minimized or "alt-tabbed" while it is loading content. - Fixed screen-shot grabbing and manual save-game thumbnails not working under OpenGL. - OpenGL library can now load even if some vendor dependent functions are missing. - X11 libraries on Linux are now dynamically loaded, so game can properly report and error if something is missing. - Dedicated server on Linux no longer requires X11 to be installed. - Fixed problems with filenames of wrong case that happened only with Linux dedicated server. - Full support for language packs in Workshop. Language mods can now work even in pure (non-moddable) version of the game, and don't require any customization from user side. Just subscribe to them. - Workshop packages menu is now also available in non-moddable version of application (this allows enabling/disabling of language packs). - User is now properly notified when Steam Workshop content download fails. - Fixed issues that might have prevented some user accounts from uploading to Workshop. - SeriousEditor now displays Steam Workshop sync progress in status bar. - Upload to Steam Workshop command is no longer available until Steam Workshop sync is finished. Previuously, it locked up the application. - Fixed an issue causing clients to always see weapon change on HUD at game start. - Fixed a lockup happening if spectator cameras are linked in a closed loop. This only happened with user-made levels. - Weapon change attempt is now correctly being indicated on HUD if performed during sprint. - Fixed popup menus in Serious Editor sometimes going off the bottom of the screen in multimonitor setups. - Fixed duplicate directory entries being shown in Serious Editor in file browsing for directories inside user-made .gro files. - Added vertex merge when importing fbx meshes. - Added facilities in Serious Editor to automate editing on entities from console scripts. - Added cfuncs edtGetMemberValue(strUserDataPath) and edtSetMemberValue(strUserDataPath, value) used to change entity properties. - Added cfunc edtSelectEntityPropertyByID(iEntityID). - On Linux, fixed wrong display settings if no monitor has been marked as primary. - KDE session version added to the log.