XPlain – Explaining X11 for the rest of us

http://magcius.github.io/xplain/article/index.html

by emillon • 12 years ago

329 65 12 years ago

magcius.github.io

ivanche2• 12 years ago

Ah, by the title I thought it's about crypto currencies and X11 algorithm...

jimktrains22• 12 years ago

X11 is a protocol, not an algorithm.

ivanche2• 12 years ago

Thanks for the correction! And I wondered why I got all those downvotes...

Flimm2• 12 years ago

This article was last updated in May 2014:

https://github.com/magcius/xplain/commits/gh-pages

Jasper_12• 12 years ago

I have plans and some code for the next article, but I've been busy with actual real work. I promise you'll see it before the end of the year.

Flimm2• 12 years ago

Sorry, I should have been more clear. I was pleasantly surprised by how recent the updates are and many commits there were. Keep up the good work!

lucian19004• 12 years ago

Actually embedding an X server in the article is one of the coolest things I've seen in a while.

pjc502• 12 years ago

That's a seriously awesome piece of work. I'm sure it could be used for more things than demos.

X11's client-server model is seriously underappreciated, and the continuing efforts to make X behave exactly like Microsoft Windows frequently forget about network transparency.

Conversely, trying to make X behave like Microsoft Remote Desktop is often unreasonably painful. I've not yet seen a nice solution for detaching and reattaching X applications like screen(1)

XorNot2• 12 years ago

This is an ongoing complaint I have with X: remote desktop on Windows systems is still far superior to Linux systems.

Jasper_12• 12 years ago

I wrote the server from scratch JavaScript, and I can't verify its accuracy towards real server behavior:

https://github.com/magcius/xplain/blob/gh-pages/src/server/s...

It's fake in a lot of ways, especially in its input model. It's well-commented and designed as a codebase to learn from, not as a real implementation of an X server that's reusable.

lucian19004• 12 years ago

I don't think X11's network transparency is useful at all nowadays. RDP and VNC give much better results.

Wayland's model is much more likely to end up with useful network support.

Modern graphics simply does not scale across networks naively.

ZeroGravitas• 12 years ago

Have you tried Xpra?

It bills itself as "screen for X"

https://www.xpra.org/

omnibrain• 12 years ago

The article about the linux graphics stack that he links right at the beginning is also very interesting.

Shish2k• 12 years ago

you might remember that Xorg was forked from XFree86 a decade ago

Today's xkcd is relevant :( ( http://xkcd.com/1393/ )

ccozan• 12 years ago

Ah, the magic of X. I've done my first steps into X by programming a graphical FTP client on a SGI Indy 2 under IRIX. It was 1994 and I spent about 3 weeks and I had luck to get the O'Reilly X books [0] ( and other two, can't remember ).

[0] http://shop.oreilly.com/product/9781565920156.do

jesuslop3• 12 years ago

I hope Wayland innards gets similar efforts to be explained and publicised with this same level of quality as this piece on venerable x11.

Jasper_12• 12 years ago

I'm trying: http://blog.mecheye.net/2014/06/xdg-shell/

Really, a big part of Wayland is that there isn't much there. It's not a ridiculously complicated system to explain with lots of extensions, you're just having clients pass image files around and get streams of messages for input. The easiest way to get a feel for the system is to use the built-in protocol dumper:

  $ WAYLAND_DEBUG=client weston-terminal

... or so... and that's it, that's the entire system.

If anybody has any more questions on Wayland internals, I'll certainly consider writing a series of articles on it.

pjc502• 12 years ago

Interesting, that's the most positive thing I've heard about Wayland so far (much simpler system).

forgottenpass• 12 years ago

It's not a ridiculously complicated system to explain

So I don't know much about the wayland architecture outside of the docs and Daniel Stone's linux.conf.au talk on it. It seemed like a clean and smart replacement to what X has become, after using it for a while have you run into any serious limitations or is everything still going along smoothly?

I've poked my head in a few times, but is there anywhere good to keep up on progress other than the mailing lists?

jesuslop3• 12 years ago

Nice piece. And a quicky, can a compositor be a client of another?

angersock• 12 years ago

What are some other good resources for learning X? It seems like quite the dark art.

jesuslop3• 12 years ago

You can look here, they have a tutorial and a web version of the XLib Manual:

http://tronche.com/gui/x

Jasper_12• 12 years ago

I would recommend against the Tronche site for references. It was automatically converted, but there are sometimes fields missing in places. I've tried emailing him, but the email address is disconnected. You can find reference documentation officially here:

http://www.x.org/releases/current/doc/libX11/libX11/libX11.h... http://www.x.org/releases/current/doc/xorg-docs/icccm/icccm....

I haven't read the tutorial, so maybe that's perfectly OK.

rdvrk• 12 years ago

Beautifully done; the writing style, the server running inside my browser - wow!

I haven't been so excited about a piece of software for ages. Reading this and looking at demos gives me the same feeling of amazement I got reading paper magazines when I was younger. Exploring floppies included with books, hearing the modem connecting for the first time, short pause, stream of characters before the login prompt. Magical.

Thank you Jasper_ for doing this and emillion for the link.

peaton2• 12 years ago

Slightly unrelated, but does all of this recent github hacking for blogs/books/etc remind anyone else of myspace?

Jasper_12• 12 years ago

I chose GitHub because it's an easy way to publish a static website that I don't have to rsync: contributors can fix a typo and I press a button on the website and things are automatically deployed.

It's a super convenient workflow for me, and there's nothing else like it in my opinion. If there is, please let me know! I hate rsync / scp for deploying static sites, but that's the best thing we have right now.

peaton2• 12 years ago

I'm not saying it's a bad thing. I really just meant it as a comment. Hacking the layout just reminded me of those good old myspace profile days. No I'm not "hating". Everybody does this these days. I just think it's interesting.

XPlain – Explaining X11 for the rest of us

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