manipulate X11 keymaps (for xmodmap) graphically

 xkeycaps is a graphical front-end to xmodmap(1). 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. This
 program can also write an input file for xmodmap to recreate your changes in
 future sessions.