Lightweight Window Managers and Desktops

Full desktop environments like GNOME and KDE Plasma are polished and feature-rich, but they consume significant RAM, load many background services, and make assumptions about how you want to work. Lightweight window managers hand control back to you: boot into a 200 MB RAM footprint, compose your own toolchain, and build a workflow that does exactly what you need — nothing more. This guide covers the most practical options (i3, Sway, and Openbox), how to install and configure each, and how to decide which fits your situation.

Choosing the Right Tool

Before installing anything, understand the landscape:

• i3 — X11 tiling WM. Keyboard-driven, scriptable, massive community, extensive documentation. Works everywhere X11 does.
• Sway — Wayland tiling WM, drop-in spiritual successor to i3. Nearly identical config syntax, but native Wayland. Prefer this on modern hardware unless you need specific X11-only software.
• Openbox — X11 floating WM. Stacking window manager with right-click menus, minimal resource use, works well as the WM beneath LXDE or standalone. Good for users transitioning from traditional desktops.

A rough decision rule: new hardware with no X11 dependencies → Sway. Need X11 or running on older hardware → i3. Want a traditional floating layout with minimal overhead → Openbox.

Installing a Lightweight WM

i3 (X11)

Debian/Ubuntu:

sudo apt install i3 i3status dmenu xterm

Fedora/RHEL family:

sudo dnf install i3 i3status dmenu xterm

Arch:

sudo pacman -S i3-wm i3status dmenu xterm

On Arch, i3-wm is the window manager package; i3 is a group that also pulls in i3lock and i3status.

Sway (Wayland)

Debian/Ubuntu (22.04+):

sudo apt install sway swaybar swaybg swaylock waybar foot

Fedora:

sudo dnf install sway waybar foot

Arch:

sudo pacman -S sway waybar foot swaylock swayidle

foot is a fast Wayland-native terminal. You can substitute alacritty or kitty if preferred.

Openbox (X11 floating)

Debian/Ubuntu:

sudo apt install openbox obconf lxappearance tint2 feh

Fedora:

sudo dnf install openbox obconf tint2 feh

Arch:

sudo pacman -S openbox obconf tint2 feh

Starting Your WM

From a Display Manager

Most display managers (GDM, SDDM, LightDM) detect installed session files automatically. After installation, log out and choose the new session from your login screen's session selector. i3 and Openbox install .desktop files into /usr/share/xsessions/; Sway installs into /usr/share/wayland-sessions/.

Without a Display Manager (TTY login)

For i3 or Openbox, add this to ~/.bash_profile or ~/.zprofile:

[[ -z $DISPLAY && $XDG_VTNR -eq 1 ]] && exec startx

Then set ~/.xinitrc:

exec i3
# or: exec openbox-session

For Sway from TTY:

[[ -z $WAYLAND_DISPLAY && $XDG_VTNR -eq 1 ]] && exec sway

Basic Configuration

i3 and Sway

On first launch, i3 asks you to generate a default config. Accept, or copy the default manually:

mkdir -p ~/.config/i3
cp /etc/i3/config ~/.config/i3/config

Sway's config lives at ~/.config/sway/config. The syntax is nearly identical to i3. Key directives to know:

# Set modifier key (Mod4 = Super/Win key)
set $mod Mod4

# Launch terminal
bindsym $mod+Return exec foot

# Application launcher (wofi for Wayland, dmenu for X11)
bindsym $mod+d exec wofi --show run

# Reload config
bindsym $mod+Shift+r reload

# Kill focused window
bindsym $mod+Shift+q kill

# Switch workspaces
bindsym $mod+1 workspace number 1

The tiling model in i3/Sway splits the screen into containers. By default Mod+Enter opens a terminal, Mod+h/v switches split direction, and Mod+f toggles fullscreen. Everything is reachable without a mouse once you learn the bindings.

Status Bar

i3 ships with i3status and reads ~/.config/i3status/config. A minimal example:

general {
  interval = 5
}

order += "disk /"
order += "memory"
order += "tztime local"

disk "/" {
  format = "%avail"
}

memory {
  format = "%used / %total"
  threshold_degraded = "1G"
}

tztime local {
  format = "%Y-%m-%d %H:%M"
}

For Sway, waybar is the de facto standard and supports Wayland properly. Its config at ~/.config/waybar/config is JSON-based; the default installed config is a working starting point.

Openbox

Openbox stores per-user config in ~/.config/openbox/. Populate it from system defaults:

mkdir -p ~/.config/openbox
cp /etc/xdg/openbox/{rc.xml,menu.xml,autostart} ~/.config/openbox/

The right-click desktop menu is defined in menu.xml. Add application launchers there. The autostart file runs commands at session start — set wallpaper and start your panel:

feh --bg-scale ~/Pictures/wallpaper.jpg &
tint2 &

obconf provides a GUI for themes and window behavior. lxappearance controls GTK themes across all apps.

Essential Supporting Software

A bare WM handles only window placement. You will typically also want:

• Application launcher: dmenu or rofi (X11), wofi or fuzzel (Wayland)
• Notification daemon: dunst (works on both X11 and Wayland)
• Compositor: i3 has none built-in — add picom for transparency/shadows. Sway and Openbox (with a compositor) handle this differently; Sway composites natively.
• Screen locker: i3lock (X11), swaylock (Wayland)
• PolicyKit agent: lxpolkit or polkit-gnome — needed for GUI apps that request elevated privileges
• Network manager applet: nm-applet integrates with NetworkManager and works in the system tray

Autostart with systemd User Services

For daemons you want reliably started regardless of how you log in, use systemd user units. Example for dunst:

systemctl --user enable --now dunst.service

Sway also integrates with systemd --user via sway-session.target. Any unit that declares PartOf=graphical-session.target and WantedBy=sway-session.target will start and stop with your Sway session automatically.

Verification

After logging into your new WM, confirm it is actually running:

# For i3 or Openbox (X11)
xprop -root _NET_WM_NAME
# Output will include the WM name, e.g. "i3" or "Openbox"

# For Sway
swaymsg -t get_version

Check memory footprint to confirm you gained the expected savings:

free -h

A minimal i3 or Sway session with a terminal and status bar typically sits under 300 MB total system RAM on a clean install.

Troubleshooting

No audio controls or media keys

WMs do not manage audio policy. Install pipewire + wireplumber (modern) or pulseaudio, then add keybindings in your WM config that call pactl or wpctl to adjust volume.

GTK apps look unstyled or broken

Without a full DE, GTK theme and icon settings are not applied automatically. Run lxappearance once to write ~/.gtkrc-2.0 and ~/.config/gtk-3.0/settings.ini. For GTK4 apps, set environment variable GTK_THEME=Adwaita in your session startup.

Screen sharing / screencasting fails under Sway

Wayland screen capture requires xdg-desktop-portal-wlr (or xdg-desktop-portal-hyprland if using Hyprland). Install it and ensure pipewire is running. Most browsers will then detect the portal automatically.

i3/Openbox launched but display manager still loads GNOME by default

The display manager remembers your last session. Log out, click the session chooser icon on the login screen, select your WM, then log in. It will remember the choice next time.