Thursday, December 14, 2023

Xorg being removed. What does this mean?

You may have seen the news that Red Hat Enterprise Linux 10 plans to remove Xorg. But Xwayland will stay around, and given the name overloading and them sharing a git repository there's some confusion over what is Xorg. So here's a very simple "picture". This is the xserver git repository:

$ tree -d -L 2 xserver
├── composite
├── config
├── damageext
├── dbe
├── dix
├── doc
│   └── dtrace
├── dri3
├── exa
├── fb
├── glamor
├── glx
├── hw
│   ├── kdrive
│   ├── vfb
│   ├── xfree86              <- this one is Xorg
│   ├── xnest
│   ├── xquartz
│   ├── xwayland
│   └── xwin
├── include
├── m4
├── man
├── mi
├── miext
│   ├── damage
│   ├── rootless
│   ├── shadow
│   └── sync
├── os
├── present
├── pseudoramiX
├── randr
├── record
├── render
├── test
│   ├── bigreq
│   ├── bugs
│   ├── damage
│   ├── scripts
│   ├── sync
│   ├── xi1
│   └── xi2
├── Xext
├── xfixes
├── Xi
└── xkb
The git repo produces several X servers, including the one designed to run on bare metal: Xorg (in hw/xfree86 for historical reasons). The other hw directories are the other X servers including Xwayland. All the other directories are core X server functionality that's shared between all X servers [1]. Removing Xorg from a distro but keeping Xwayland means building with --disable-xfree86 -enable-xwayland [1]. That's simply it (plus the resulting distro packaging work of course).

Removing Xorg means you need something else that runs on bare metal and that is your favourite Wayland compositor. Xwayland then talks to that while presenting an X11-compatible socket to existing X11 applications.

Of course all this means that the X server repo will continue to see patches and many of those will also affect Xorg. For those who are running git master anyway. Don't get your hopes up for more Xorg releases beyond the security update background noise [2].

Xwayland on the other hand is actively maintained and will continue to see releases. But those releases are a sequence [1] of

$ git new-branch xwayland-23.x.y
$ git rm hw/{kdrive/vfb/xfree86/xnest,xquartz,xwin}
$ git tag xwayland-23.x.y
In other words, an Xwayland release is the xserver git master branch with all X servers but Xwayland removed. That's how Xwayland can see new updates and releases without Xorg ever seeing those (except on git master of course). And that's how your installed Xwayland has code from 2023 while your installed Xorg is still stuck on the branch created and barely updated after 2021.

I hope this helps a bit with the confusion of the seemingly mixed messages sent when you see headlines like "Xorg is unmaintained", "X server patches to fix blah", "Xorg is abandoned", "new Xwayland release.

[1] not 100% accurate but close enough
[2] historically an Xorg release included all other X servers (Xquartz, Xwin, Xvfb, ...) too so this applies to those servers too unless they adopt the Xwayland release model

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