xkeycaps - 2.47-7 main

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.