The Qt XInput Extension is a C library adding support for XInput devices (like tablets or joysticks) to Qt-based X11 applications. QXi supports devices with up to six valuator axes in absolute mode, up to 32 buttons, and any number of keys. It is built using autoconf and libtool, and comes with a simple example application.
QStick is a program which uses the XTest extension in XFree86 to send keyboard messages to an X server from a Linux-supported joystick. The program consists of the KBStick executable which reads joystick input and dispatches keypress messages to X, and the QStick shell script which configures environment varibles read by the executable to assign X KeyCodes to the joystick directions & button presses.