libinput

Libinput is an open-source input device handling library for Linux. It provides a unified API for keyboards, pointers, touchpads, touchscreens, and other input devices, with a focus on use by Wayland compositors. It is also used by the X.Org project through the libinput X driver, enabling X11 environments to benefit from libinput’s input management.

Libinput obtains raw events from the kernel via the evdev interface, using libudev to detect devices. It normalizes device-specific quirks, applies calibration and filtering, and exposes high-level events to clients. The API is designed for use by compositors and input-aware applications, delivering events such as motion, button presses, scrolling, and touch activity, as well as multitouch and gesture data.

Key capabilities include multitouch tracking, gesture recognition (including taps, and two- and three-finger gestures), natural scrolling, palm detection, and device hotplug handling. Libinput also supports device reconfiguration, rotation, and calibration, and provides facilities for enabling or disabling devices and customizing behavior via configuration files or runtime options.

Development and ecosystem: Maintained by the freedesktop.org community as part of the Wayland ecosystem. It is widely integrated into major Wayland compositors such as Weston, GNOME Shell (Mutter), and KDE (KWin). Libinput ships with tooling for debugging and device inspection and offers bindings for languages beyond C in some projects.