Basically a long time ago Linux/Unix was run on big machines in a separate room with all the fancy graphics hardware, and you’d have a dumb little machine at your desk that could barely draw pixels on a screen. So X11 was designed with all these fantastic neat server-client mechanisms that made it great for running on a mainframe.
Fast forward 30 years and all that stuff is useless now that everyone has built in graphics (as well as several other issues with X11’s archaic design). So some smart people who didn’t know any better made a new thing that everything has to be rewritten for (because they were smart, but didn’t know any better). Then someone who did know a little better was like, what if we take the old bloated one and rewrite it for the new lean one. So now everything runs in an X11 session inside a Wayland server, which has to be rewritten for everything because Wayland is a protocol, not a server.
But one of the really nice things about it is that everything has to be rewritten, so we can make newer, fancier bugs.
Edit: I don’t want you to take the impression that I think Wayland is bad. Wayland is way better than X, it just sucks that we have to rewrite a bunch of stuff for it and figure out new ways of doing things that were dead simple in X, but very insecure.
Also window managers started compositing which moved 1/3 of what X was doing to the window manager. Then applications started doing their own rendering which moved another 1/3 of what X was doing to the applications. All that is left over is basically the low-level IO which had gotten greatly simpler over the years and could basically be packaged into a few libraries (mesa and libinput primarily) and some complex mutli-hop IPC which was completely unnecessary.
X11 is like a big dilapidated house. It doesn’t work very well anymore and is difficult to maintain.
Wayland is new modern house. Smaller and more efficient, but missing some amenities that the old house had that some people still want, like a wood burning stove.
Most features missing right now (not all) are against the Wayland philosophy, this doesn’t mean that you won’t get anything but that it needs a “modern era replacement”. Though applications will need to support the replacement. This is usually for good reasons.
The prime example is screen recording. Allowing any program to read and write the entire screen is objectively wrong, no matter what the big time X11 fans say. But there is a replacement: pipewire. Pipewire is extremely advanced and featureful, and it’s more secure because it allows the system and the user to audit who is reading the screen and what part. The problem is that programs need to support pipewire for screen recording, but the main culprits are niche screen recorders (OBS is the best anyway, and it supports it) and proprietary video call software like discord (zoom supports it), which is silly because for electron apps it’s literally a matter of using a version less than 3 years old an adding a flag.
I’ve recently switched to Nobara, and has been unsure whether to go with Wayland or X11. Mostly because I’ve read that Wayland has issues on NVIDIA GPUs and will perform slower, so I went with X11 (On KDE). Is that still the case nowadays, or can I just use Wayland?
Afaik the Nvidia issues are pretty much resolved now, though it may depend on exactly which GPU you use.
It’s definitely worth using Wayland if it’s not having issues, and switching back is absurdly easy, so I’d recommend using Wayland and going back to X if you’re encountering issues.
Tldr: it’ll probably be fine, give it a go and see
Back in the day X was a great protocol that reflected the needs of the time.
Applications asked it to draw some lines and text.
It sent input events to applications.
People also wanted to customize how their windows were laid out more flexibly. So the window manager appeared. This would move all of your windows around for you and provide some global shortcuts for things.
Then graphics got more complicated. All of a sudden the simple drawing primitives of X weren’t sufficient. Other than lines, text and rectangles applications wanted gradients, rounded corners and to display rich graphics. So now instead of using all of these fancy drawing APIs they were just uploading big bitmaps to the X server. At this point 1/3 of what the X server was previously doing became obsolete.
Next people wanted fancy effects and transparency (like drop shadows). So window managers started compositing the display. This is great but now they need more control than just moving windows around on the display in case they are warped, rendered somewhere slightly differently or on a different workspace. So now all input events go first from X to the window manager, then back to X, then to the application. Also output needs to be processed by the window manager, so it is sent from the client to X, then to the window manager, then the composited output is sent to X. So another 1/3 of what X was doing became obsolete.
So now what is the X server doing:
Outputting the composited image to the display.
Receiving input from input devices.
Shuffling messages and graphics between the window manager and applications.
It turns out that 1 and 2 have got vastly simpler over the years, and can now basically be solved by a few libraries. 3 is just overhead (especially if you are trying to use X over a network because input and output need to make multiple round-trips each).
So 1 and 2 turned into libraries and 3 was just removed. Basically this made the X server disappear. Now the window manager just directly read input and displayed output usually using some common libraries.
Now removing the X server is a breaking change, so it was a great time to rethink a lot of decisions. Some of the highlights are:
Accessing other applications information (output and input capture) requires explicit permission. This is a key piece to sandboxing applications.
Organize the system around frames to avoid tearing except for when desired (X doesn’t really have the concept of a frame).
Remove lots of basically unused APIs like fonts, drawing and many others.
So the future is great. Simpler, faster, more secure and more extensible. However getting there takes time.
This was also slowed down by some people trying to resist some features that X had (such as applications being able to position themselves). And with a few examples like that it can be impossible to make a nice port of an application to Wayland. However over time these features are being added and these days most applications have good Wayland support.
X is old and works for the most part but fixing stuff or adding features is hard.
Wayland is new and is supposed to be a successor to X, do what it couldn’t do and don’t repeat the mistakes from it. It should be a drop-in replacement like pipewire but isn’t. Features take long time to develop as devs are engrossed thinking of the best solution to make it happen. A lot of proposed solutions are dismissed as well.
I think the drama around Wayland can be explained by the sentence “it should be a drop-in replacement like pipewire but isn’t”.
Without taking a side on that issue, I will point out that this was not a goal for the Wayland designers ( in their own words - I do not have time to go find a quote but have read this sentiment many times ). Wayland detractors agree with your sentence and, given that expectation, are legitimately upset and even confused that Wayland continues to gain mind and market share against X11.
If you feel that Wayland needs to be a drop-in replacement for X11, it is not ready and may never be. By that metric, some people see Wayland as a failed technology and perceive Wayland users as shills and zealots.
If you are interested in a display server that addresses some of the core design problems in X11 and do not mind moving to something new, Wayland is starting to look ready for prime-time.
If you are non-technical and / or unopinionated the debate is probably irrelevant. Wayland will most likely become the default on whatever Linux distribution you use sometime in 2024 or 2025. You will be a Wayland user. Maybe you already are.
If you are willing to step outside the mainstream, using X11 without Wayland is going to be possible for at least another decade. That said, I am saying “outside the mainstream” because not only will popular Linux distributions and desktop environments start to become Wayland only but the innovation is all going to move to Wayland. There will be many Wayland-only compositors, apps, and features. 5 years from now, not using Wayland is going to really limit the desktop experience. I expect some toolkits ( GTK, Qt, and maybe even WINE ) to drop X11 support at some point ( maybe not soon but sooner than 10 years maybe ). 5 - 10 years may seem like a long time but it will likely come faster than X11 stalwarts expect.
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