g13 is a Linux-only library to interact with the Logitech G13 driver. This library provides several sublibraries including libg13, libg13mm, libg13-cairo, libg13-gtk, and libg13-gtkmm. These libraries provide functions and classes for browsing G13 devices through udev, setting the backlight color, establishing keymaps, and drawing on the G13 framebuffer device.
uhat is a tool that listens to joystick events and converts hat switch axis events into the joystick button events X-Plane needs. Some joysticks have hat switches that are represented to the OS as two axes, even though mechanically they're just four 0/1 switches. These hat switches are often used for looking around through the cockpit in X-Plane.