xhkeys allows you to assign an action to any key that is otherwise unused in X (such as the "menu" key on a 105 key keyboard, extra keys on some keyboard models, or odd keys on laptops).
The purpose of Xhotkeys is to provide a simple and easy configurable hotkey launcher for the X-Window System. It should work on all desktops (Gnome, KDE, Xfce, ...) available for GNU/Linux. Although Xhotkeys has a graphical GTK+ configurator, it's possible to manage the configuration file manually.
a graphical front-end to xmodmap. It opens a window that looks like a keyboard; moving the mouse over a key shows what KeySyms and Modifier bits that key generates. Clicking on a key simulates KeyPress/KeyRelease events on the window of your choice. It is possible to change the KeySyms and Modifiers generated by a key through a mouse-based interface
xkeysw is a keyboard layout switch for X-windows.
xlax is an X11 input multiplexer: it sends your keyboard input from the xlax window to a group of windows simultaneously. The tool is designed for system administrators who typically have to do the same thing on several machines (or in several different directories).
xrebind allows you to bind keys or buttons. These can be used to generate mouse motions, button presses or releases, key presses or releases, or to launch programs.
a simple tool that lets you grab the mouse and keyboard of another machine and control them with your local mouse and keyboard. It creates a form of remote control of other machine
xvkbd is a virtual (graphical) keyboard program for X Window System which provides facility to enter characters onto other clients (softwares) by clicking on a keyboard displayed on the screen.
a Vietnamese keyboard input for X-Window. It provides an useful way for editing Vietnamese on X-Window environment with popular input methods and charsets. This software released under GNU GPL license