KDE turned 30 on October 14 and celebrated with a new Plasma release, a documentary about the project and one big goodbye. Plasma 6.8, branded the "30th Anniversary Edition", no longer starts native X11 sessions.
What changes for you
Plasma now lives on Wayland only. Old X11 programs still run through the XWayland compatibility layer, and KDE's own apps will keep supporting X11 when they are used under other desktops. If you stay on Plasma 6.7, your current X11 session is left alone for now. The step was expected, since GNOME already stopped offering X11 sessions by default in 2025.
What is new
Third-party apps can get window shadows and rounded corners, the Union theming system has been simplified, and Nvidia triple buffering is switched on by default. The Kup backup tool is now built into Plasma, and a new command line utility called kscreenctl lets power users change display settings from the terminal.
Should you upgrade
Most desktop users will not notice the switch. If your daily routine depends on tools that only speak X11, test the upgrade on a spare machine first.