Source: https://linux-hardware.org/?view=os_display_server
Reporting is done by users who voluntarily upload their system specs via
# hw-probe -all -upload
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
Doesn't steam deck use x11?
After doing some sniffing: Yes AND no
The default "gaming mode" that the Deck boots into is running wayland, specifically valve's own gamescope compositor which has a lot of workarounds and breaks from wayland's spec to allow for better gaming performance.
When you quit out to "desktop mode" it loads into KDE Plasma with X11, although with recent changes to Plasma, it may well be that the desktop mode will change to being wayland based too.