[kunzhi]

Interesting article, I'll admit when I first saw the title I was thinking of a different kind of "scaling" - namely the client/server decoupling in X11.

I still think X11 forwarding over SSH is a super cool and unsung/undersung feature. I know there are plenty of good reasons we don't really "do it these days" but I have had some good experiences where running the UI of a server app locally was useful. (Okay, it was more fun than useful, but it was useful.)

[xioxox]

It's certainly very useful. I do half my work using X11 over ssh and it works reasonably well over a LAN (at least using emacs, plotting, etc).

[inetknght]

"reasonably well" as in... yeah it works. But it's extremely laggy (for comparison, I know people who forwarded DirectX calls over 10Mbit ethernet and could get ~15 frames/sec playing Unreal Tournament in the early 00's), and any network blip is liable to cause a window that you can neither interact with nor forcefully close.

It felt like a prototype feature that never became production-ready for that reason alone. Then there's all the security concerns that solidify that.

But yes, it does work reasonably well, and it is actually really cool. I just wish it were... better.

[uecker]

It is laggy but not because of protocol limitations but due to Xlib not being able to hide the latency and we never got the proper support from toolkits to do this via XCB. Xpra or other proxys work around this, but it would be nice if toolkits supported this directly. Also reconnect or moving windows between displays would be no problem if toolkits supported this.

[welterde]

For applications that were written with X11 in mind it works much much better than that. One example was the controlling a telescope. The computers in the control room were thin clients pretty much and displayed various windows from various machines across the mountain - even across multiple different operating systems! Some machines were running Solaris and some linux. The different machines belonged to different aspects of the telescope: some controlled the telescope itself and some machines belonged to the different scientifc instruments on the telescope. And it all worked quite well with no real noticeable lag.

[DonHopkins]

I worked on the NeWS drivers for Emacs (both "Evil Software Hoarder" Gosling UniPress Emacs 2.20 and later "Free" Gnu Emacs 18), which were extremely efficient and smoothly interactive over low baud rate modems (which we called "thin wire" as opposed to i.e. the "thick wire" coaxial 10BASE5 Ethernet of the time), because instead of using the extraordinarily inefficient, chatty, pong-pongy X-Windows protocol, Emacs could simply download PostScript code to the window server that defined a highly optimized application specific client/server protocol and intelligent front-end (now termed "AJAX"), which performed as much real time interaction in the window system as possible, without any network activity, like popping up and tracking pie menus, and providing real time feedback and autoscroll when selecting and highlighting text.

For example, both versions of Emacs would download the lengths of each line on the screen when you started a selection, so you could drag and select the text and animation the selection overlay without any network traffic at all, without sending mouse move events over the network, only sending messages when you autoscrolled or released the button.

http://www.bitsavers.org/pdf/sun/NeWS/800-5543-10_The_NeWS_T... document page 2, pdf page 36:

>Thin wire

>TNT programs perform well over low bandwidth client-server connections such as telephone lines or overloaded networks because the OPEN LOOK components live in the window server and interact with the user without involving the client program at all.

>Application programmers can take advantage of the programmable server in this way as well. For example, you can download user-interaction code that animates some operation.

UniPress Emacs NeWS Driver:

https://github.com/SimHacker/NeMACS/blob/b5e34228045d544fcb7...

Selection support with local feedback:

https://github.com/SimHacker/NeMACS/blob/b5e34228045d544fcb7...

Gnu Emacs 18 NeWS Driver (search for LocalSelectionStart):

https://donhopkins.com/home/code/emacs18/src/tnt.ps

https://news.ycombinator.com/item?id=26113192

DonHopkins on Feb 12, 2021 | parent | context | favorite | on: Interview with Bill Joy (1984)

>Bill was probably referring to what RMS calls "Evil Software Hoarder Emacs" aka "UniPress Emacs", which was the commercially supported version of James Gosling's Unix Emacs (aka Gosling Emacs / Gosmacs / UniPress Emacs / Unimacs) sold by UniPress Software, and it actually cost a thousand or so for a source license (but I don't remember how much a binary license was). Sun had the source installed on their file servers while Gosling was working there, which was probably how Bill Joy had access to it, although it was likely just a free courtesy license, so Gosling didn't have to pay to license his own code back from UniPress to use at Sun. https://en.wikipedia.org/wiki/Gosling_Emacs

>I worked at UniPress on the Emacs display driver for the NeWS window system (the PostScript based window system that James Gosling also wrote), with Mike "Emacs Hacker Boss" Gallaher, who was charge of Emacs development at UniPress. One day during the 80's Mike and I were wandering around an East coast science fiction convention, and ran into RMS, who's a regular fixture at such events.

>Mike said: "Hello, Richard. I heard a rumor that your house burned down. That's terrible! Is it true?"

>RMS replied right back: "Yes, it did. But where you work, you probably heard about it in advance."

>Everybody laughed. It was a joke! Nobody's feelings were hurt. He's a funny guy, quick on his feet!

In the late 80's, if you had a fast LAN and not a lot of memory and disk (like a 4 meg "dickless" Sun 3/50), it actually was more efficient to run X11 Emacs and even the X11 window manager itself over the LAN on another workstation than on your own, because then you didn't suffer from frequent context switches and paging every keystroke and mouse movement and click.

The X11 server and Emacs and WM didn't need to context switch to simply send messages over the network and paint the screen if you ran emacs and the WM remotely, so Emacs and the WM weren't constantly fighting with the X11 server for memory and CPU. Context switches were really expensive on a 68k workstation, and the way X11 is designed, especially with its outboard window manager, context switching from ping-ponging messages back and forth and back and forth and back and forth and back and forth between X11 and the WM and X11 and Emacs every keystroke or mouse movement or click or window event KILLED performance and caused huge amounts of virtual memory thrashing and costly context switching.

Of course NeWS eliminated all that nonsense gatling gun network ping-ponging and context switching, which was the whole point of its design.

That's the same reason using client-side Google Maps via AJAX of 20 years ago was so much better than the server-side Xerox PARC Map Viewer via http of 32 years ago.

https://en.wikipedia.org/wiki/Xerox_PARC_Map_Viewer

Outboard X11 ICCCM window managers are the worst possible most inefficient way you could ever possibly design a window manager, and that's not even touching on their extreme complexity and interoperability problems. It's the one program you NEED to be running in the same context as the window system to synchronously and seamlessly handle events without dropping them on the floor and deadlocking (google "X11 server grab" if you don't get what this means), but instead X11 brutally slices the server and window manager apart like King Solomon following through with his child-sharing strategy.

https://tronche.com/gui/x/xlib/window-and-session-manager/XG...

While NeWS not only runs the window manager efficiently in the server without any context switching or network overhead, but it also lets you easily plug in your own customized window frames (with tabs and pie menus), implement fancy features like rooms and virtual scrolling desktops, and all kinds of cool stuff! At Sun were even managing X11 windows with a NeWS ICCCM window manager written in PostScript, wrapping tabbed windows with pie menus around your X-Windows!

https://donhopkins.com/home/archive/NeWS/owm.ps.txt

https://donhopkins.com/home/archive/NeWS/win/xwm.ps

https://www.donhopkins.com/home/catalog/unix-haters/x-window...