libinput
also: libinput library
libinput is a library that handles input devices (mice, keyboards, touchpads, touchscreens) for Linux, providing a unified interface between hardware and desktop environments.
libinput abstracts the complexity of different input device types and manufacturers, allowing applications and desktop environments like GNOME and KDE to interact with input hardware through a single, consistent API rather than writing device-specific code.
It manages event processing, acceleration curves, gesture recognition, and calibration for devices such as mice, trackpads, styluses, and touch screens. For example, libinput interprets raw touchpad data into meaningful gestures like two-finger scrolling or pinch-to-zoom.
Most modern Linux distributions use libinput as the default input handling layer, replacing older systems like Xorg's input drivers. You typically don't interact with libinput directly—it works silently in the background—but configuration can be done through desktop environment settings or by modifying /etc/libinput/ configuration files.