"It is intended to eventually replace the classic X.org server in Alpine, thus reducing maintenance burden of X applications in Alpine, but a lot of work needs to be done first."
OT but what's the use case for running gui applications in alpine? I've mostly seen it used as a container OS on servers. Are people using it for kiosks?
AIUI: you need an existing compositor to run Xwayland.
An X server is a display server: it can run on its own, and apps can output to it, with nothing else running. When one program runs early on and provides windows furniture, that's a window manager.
If that program (or associated ones with a uniform look and feel) also provides UI functionality so you don't need to use a command prompt, such as tools to launch apps, see and manage files, edit text files, mount and unmount media, and maybe things like see the time, adjust system settings, do calculations, etc. then that is called a desktop environment.
Wayland is not like this. Wayland is a protocol. There are no separate display servers. What under X is called a "window manager" usually talks Wayland and so other apps talk directly to the WM over Wayland in order to display stuff.
There's no bottom layer program, no server. The WM is the display server. Without a WM you can't run anything.
That means you need a Wayland compositor to run anything else, such as XWayland.
This means that you can't use an X WM to be the compositor, because the layer needed to run the WM is not there until another different app provides the Wayland environment, and then it's the WM and your X WM can't take over. Remove the compositor, there's no GUI.
This is not a question of whipping out the tablecloth from under a fully-laid table. It's removing the table.
So what this project looks like is a compositor that isn't a WM and so enables Xwayland to run full-screen as the root window, letting you use an X WM as your desktop with no Wayland WM.
It sounds of great interest to me because whereas there are about half a dozen X desktops and environments I like, some I've been using for decades now, there is not a single Wayland environment I would be willing to use.
This just feels like the kind of thing the people who built Wayland should have focussed on for their first real release, as that would have allowed them to simply deprecate X11 immediately with a "better" architecture rather than go to war for a decade (and build up a ton of bad will in the process) forcing people to first try to make major adaptations to everything.
It uses XWayland under the hood -- it is an implementation of rootful XWayland that is presumably properly integrated, rather than being glued to a window. Meaning you get the full Xorg desktop, and things like panels will (hopefully) properly snap to the side of the screen instead of displaying as a window.
"Wayback is an experimental X compatibility layer which allows for running full X desktop environments using Wayland components. It is essentially a stub compositor which provides just enough Wayland capabilities to host a rootful Xwayland server."
"It is intended to eventually replace the classic X.org server in Alpine, thus reducing maintenance burden of X applications in Alpine, but a lot of work needs to be done first."
OT but what's the use case for running gui applications in alpine? I've mostly seen it used as a container OS on servers. Are people using it for kiosks?
Alpine is a full distro. It's perfectly capable of being used as a desktop OS and I do so myself.
I think this probably makes more sense for people who want to keep using x11 environments than trying to fork/maintain xorg.
Very naive question, but what is the difference between this and XWayland?
AIUI: you need an existing compositor to run Xwayland.
An X server is a display server: it can run on its own, and apps can output to it, with nothing else running. When one program runs early on and provides windows furniture, that's a window manager.
If that program (or associated ones with a uniform look and feel) also provides UI functionality so you don't need to use a command prompt, such as tools to launch apps, see and manage files, edit text files, mount and unmount media, and maybe things like see the time, adjust system settings, do calculations, etc. then that is called a desktop environment.
Wayland is not like this. Wayland is a protocol. There are no separate display servers. What under X is called a "window manager" usually talks Wayland and so other apps talk directly to the WM over Wayland in order to display stuff.
There's no bottom layer program, no server. The WM is the display server. Without a WM you can't run anything.
That means you need a Wayland compositor to run anything else, such as XWayland.
This means that you can't use an X WM to be the compositor, because the layer needed to run the WM is not there until another different app provides the Wayland environment, and then it's the WM and your X WM can't take over. Remove the compositor, there's no GUI.
This is not a question of whipping out the tablecloth from under a fully-laid table. It's removing the table.
So what this project looks like is a compositor that isn't a WM and so enables Xwayland to run full-screen as the root window, letting you use an X WM as your desktop with no Wayland WM.
It sounds of great interest to me because whereas there are about half a dozen X desktops and environments I like, some I've been using for decades now, there is not a single Wayland environment I would be willing to use.
This just feels like the kind of thing the people who built Wayland should have focussed on for their first real release, as that would have allowed them to simply deprecate X11 immediately with a "better" architecture rather than go to war for a decade (and build up a ton of bad will in the process) forcing people to first try to make major adaptations to everything.
Very clearly written, thank you.
It uses XWayland under the hood -- it is an implementation of rootful XWayland that is presumably properly integrated, rather than being glued to a window. Meaning you get the full Xorg desktop, and things like panels will (hopefully) properly snap to the side of the screen instead of displaying as a window.
From the README:
"Wayback is an experimental X compatibility layer which allows for running full X desktop environments using Wayland components. It is essentially a stub compositor which provides just enough Wayland capabilities to host a rootful Xwayland server."