xcompmgr

xcompmgr [options]

-c
    Enables client-side shadows, which are typically faster but might be less accurate for some applications.

-r radius
    Sets the shadow blur radius (default: 12).

-o opacity
    Sets the shadow opacity (default: 0.75).

-l offset
    Sets the shadow left offset (default: -15).

-t offset
    Sets the shadow top offset (default: -15).

-s
    Enables server-side shadows, which are drawn by the X server (less common now).

-f
    Enables fading effects for windows (fade in on creation, fade out on destruction).

-D step
    Sets the fade step for fade-in (default: 0.03).

-I duration
    Sets the fade-in duration in milliseconds (default: 200).

-O duration
    Sets the fade-out duration in milliseconds (default: 200).

-C
    Disables shadows on dock/toolbar windows (e.g., _NET_WM_WINDOW_TYPE_DOCK).

-S
    Disables shadows on splash screen windows (e.g., _NET_WM_WINDOW_TYPE_SPLASH).

-F
    Disables fading when unredirecting windows (e.g., fullscreen applications).

-k
    Ignores shaped windows (windows with non-rectangular outlines).

-n rule
    Specifies an opacity rule for windows based on their properties, e.g., !name = "xterm":80.

-z
    Disables the use of ARGB visual, falling back to older methods.

-vsync
    Enables vertical synchronization to prevent screen tearing.

-display display
    Specifies the X display to connect to.

-help
    Displays a help message and exits.

xcompmgr is a lightweight and standalone composite manager for the X Window System. It enables various visual effects such as drop shadows for windows, real-time window transparency, and fading effects for window opening and closing. Designed to be simple and unobtrusive, it provides basic compositing functionality without the overhead of a full desktop environment. It's often used with minimalistic window managers like Openbox, Fluxbox, or i3 to add a touch of modern aesthetics to a lightweight setup. While more advanced compositors like Picom or the built-in compositors of modern desktop environments offer richer features, xcompmgr remains a viable option for users seeking a simple and resource-friendly way to enhance their X desktop with subtle visual flair.

xcompmgr provides only basic compositing features. More advanced visual effects, animations, or robust tear-free rendering might require a more modern and feature-rich compositor like Picom. It is not actively developed and maintained as much as it once was, and some configurations might still experience screen tearing without the -vsync option or proper driver setup.

To use xcompmgr, you typically start it automatically when your X session begins. This can be done by adding a line like xcompmgr -c -r 9 -o .9 -l -15 -t -15 -f -D 5 -vsync & to your ~/.xinitrc file, or your window manager's autostart script (e.g., ~/.config/openbox/autostart for Openbox). The & symbol ensures it runs in the background.

Developed as part of the X.Org project, xcompmgr emerged as an early solution to bring basic compositing capabilities to the X Window System. Its primary goal was to provide a lightweight way to add visual enhancements like shadows and transparency, which were becoming standard in more feature-rich desktop environments. It played a significant role in enabling these effects for minimal window managers before the advent of more sophisticated compositors, and its design influenced later, more advanced projects.

picom(1), compton(1), X(7)