X Keyboard Extension -------------------- The X Keyboard Extension essentially replaces the core protocol definition of keyboard. The extension makes possible to clearly and explicitly specify most aspects of keyboard behaviour on per-key basis and to more closely track the logical and physical state of the keyboard. It also includes a number of keyboard controls designed to make keyboards more accessible to people with physical impairments. There are five types of components in the server database corresponing to five xkb symbolic names: symbols, geometry, keycodes, compat and types which determine the keyboard behaviour. These five components can combined together into a resulting keyboard mapping using the 'rules' component. More information, including the complete specification, can be found on http://www.x.org/wiki/XKB