Plwm – An X11 window manager written in Prolog
21 comments
·May 25, 2025eikenberry
pyinstallwoes
I wish more things were protocols instead of APIs.
linux2647
Could you explain the difference?
spicybright
I'm not the most knowledgeable, but a protocol talks to another process through a specific format.
I personally think its more powerful than writing a new process to replace and existing.
My favorite example is an X11 windows manager implementing in about 18 lines of python.
Obviously there's dependencies to talk to the X server, but the power of a protocol comes from any program written in any la gage communicate with existing code.
smikhanov
Looked at the source, it’s so compact, wow.
B1FF_PSUVM
Why am I reminded of the all-Erlang HN first page?
pona-a
Fun fact: the first version of Erlang interpreter was written in Prolog.
YeGoblynQueenne
Oh wow, I gotta try this.
Lots of documentation! Awesome!
gatane
Time to do one in Scheme, I guess.
pona-a
Here's one in Guile Scheme.
igorhvr
This one is customizable in Lisp, and overall pretty neat: https://sawfish.tuxfamily.org/ - I have been happily using it daily for many years now. :-)
mhd
Done a while ago: https://en.wikipedia.org/wiki/Scwm
There was also "GWM", based on its own lisp dialect, "WOOL", which was around from at least the early 90s.
On the more popular side, you had sawfish (using an elisp-alike, IIRC) and stumpwm (Common Lisp).
tmtvl
Already exists: https://github.com/mwitmer/guile-wm
There might also be ones in other Schemes, but as FFI hasn't been standardised across Schemes yet I doubt there's an implementation-agnostic one.
DonHopkins
Here's an X11 window manager, with pie menus and tabbed windows, entirely written in object oriented NeWS PostScript, from around 1991:
https://donhopkins.com/home/archive/NeWS/owm.ps.txt
And some design notes and emails on that NeWS based window manager for X11 windows:
https://donhopkins.com/home/archive/NeWS/i39l.txt
It incorporated NeWS tabbed windows written in PostScript, which could wrap around X11 windows (and frame NeWS windows too of course):
https://donhopkins.com/home/archive/NeWS/win/tab.ps
And NeWS pie menus written in PostScript, which you could pop up on tabbed window frames and manage X11 windows (and use in NeWS apps too of course):
https://donhopkins.com/home/archive/NeWS/win/pie.ps
There was also a virtual large scrolling desktop, and virtual multi-screen "rooms", both purely written in PostScript, which all plugged together with the tabbed windows and pie menus and X window manager seamlessly. They were all independent of each other and could be used separately, but worked together synergistically. Take that, ICCCM! ;)
Also here's a (pre-ICCCM, pre-X11) X10 window manager with pie menus, written in C and scripted in Forth, from around 1986:
https://donhopkins.com/home/archive/piemenu/uwm/fuwm-main.f
And some of my thoughts on X-Windows and ICCCM window management in general:
https://donhopkins.medium.com/the-x-windows-disaster-128d398...
>In summary, ICCCM is a technological disaster: a toxic waste dump of broken protocols, backward compatibility nightmares, complex nonsolutions to obsolete nonproblems, a twisted mass of scabs and scar tissue intended to cover up the moral and intellectual depravity of the industry’s standard naked emperor.
>Using these toolkits is like trying to make a bookshelf out of mashed potatoes." -Jamie Zawinski
agumonkey
First time I ever get the chance to see object postcript/forth, thank you
rclkrtrzckr
Isn't ".pl" actually used for perl?
Well, there might be a Prolog interpreter written in (a) perl (regex) ...
ajdude
Prolog was using .pl for a bit over a decade before Perl existed.
tikhonj
It's used for both which consistently confuses logic that guess programming language purely based on file extensions.
jimjimjim
Prolog is a older than Perl and there doesn't need to be any exclusive claim on file extensions.
leephillips
Very nice. If you’re used to dwm this should be natural. Unless you use dwm’s tags as more than workspaces, which I do. The author does not, so he implemented workspaces instead of tags. So this can not replace dwm for me.
reramuyc
[dead]
I'm hoping one day someone will write a window-manager service for Wayland that replaces the compositor API with a protocol. To once again enable window managers to be implemented in any language, regardless of it having a Wayland/compositor library.