zwm

Work in progress. Core functionality is implemented but not yet battle-tested. Expect rough edges.

A window manager that gets out of your way.

37KB of Zig. No Xlib. No bar. No opinions. Just windows on a screen, exactly where you put them.

Built for a HackberryPi Zero — a 720x720 screen, 512MB of RAM, and a keyboard that fits in your palm. If it runs there, it runs anywhere.

Why

Most window managers carry the weight of features you'll never touch. zwm carries nothing. One layout. Nine tags. A border that changes color when you look at it. That's the whole thing.

The configuration lives in Zig source. Change a constant, rebuild in under a second. No parser, no runtime, no surprises. The compiler catches your mistakes before the window manager ever runs.

What you get

• xcb direct — talks to the X server without Xlib in between
• Master+stack — one window leads, the rest follow
• 9 tags — bitmask, not workspaces. A window can live in two places at once
• Multi-monitor — XRandR. Plug in a screen, it appears
• Floating — dialogs know what they are. Mod+drag for everything else
• EWMH — your status bar still works

Build

git clone https://github.com/midasdf/zwm.git
cd zwm
zig build

That's it. For the smallest possible binary:

zig build -Doptimize=ReleaseSmall   # → 37KB

Dependencies

Zig 0.15+ and two libraries:

# Arch
sudo pacman -S zig libxcb xcb-util-keysyms

# Debian/Ubuntu
sudo apt install libxcb1-dev libxcb-keysyms1-dev libxcb-randr0-dev
# Zig: https://ziglang.org/download/

Install

sudo cp zig-out/bin/zwm /usr/local/bin/

# ~/.xinitrc
exec zwm

Keys

Everything is Mod (Super) plus something.

Key	What it does
Return	Open a terminal
p	Open rofi
j / k	Focus next / previous
h / l	Shrink / grow master
Space	Swap with master
Shift+Space	Float / unfloat
f	Fullscreen
Shift+c	Close window
i / d	More / fewer masters
1–9	View tag
Shift+1–9	Send to tag
, / .	Previous / next monitor
Shift+, / .	Send to monitor
Shift+q	Quit

Floating windows: Mod+Button1 to move, Mod+Button3 to resize.

Configure

There is no config file. There is src/config.zig:

pub const master_factor: f32 = 0.55;
pub const gap_px: u16 = 0;
pub const border_px: u16 = 1;
pub const border_color: u32 = 0x444444;
pub const border_focus_color: u32 = 0xBBBBBB;

Change it. Rebuild. The compiler will tell you if you did something wrong.

Develop

Test without touching your running session:

Xephyr -br -ac -noreset -screen 720x720 :1 &
DISPLAY=:1 zig-out/bin/zwm

Run the test suite:

zig build test

Inside

src/
├── main.zig       where it starts and where it loops
├── wm.zig         where windows live and die
├── xcb.zig        the thin line between Zig and X11
├── layout.zig     pure math, no side effects
├── monitor.zig    screens come and go
└── config.zig     the only file you should edit

Six files. ~2100 lines. Nothing is hidden.

vs dwm

	dwm	zwm
Written in	C	Zig
Talks to X via	Xlib	xcb
Config language	C preprocessor	Zig comptime
Layouts	3	1
Has a bar	Yes	No
Binary	~40KB	~37KB

Tags

Nine bits. Each window has them. Each monitor shows some of them.

A window can wear tag 1 and tag 3. Show both tags, see the window. Show just tag 2, it's gone. Simple as set intersection.

Status bar

zwm has no bar. It speaks EWMH — _NET_CURRENT_DESKTOP, _NET_ACTIVE_WINDOW, _NET_WM_STRUT_PARTIAL — so any bar that listens will hear it.

i3blocks, polybar, lemonbar. They all work.

License

MIT