My description wasn't very clear. I'm looking for a FOSS tool to replicate the fancy (e.g. Mac screencasts) on-screen display of the keystrokes used while interacting with the program being demonstrated.
It's usually a semi-transparent overlay in a fixed-position on the screen.
C-x k <return> ( each line ... fades out ...)
C-x 0 C-x b <right> <return>
<S-iso-lefttab> <tab> M->
<tab> <down> <tab> M-e M-e M-e M-e
Emacs has a way to show this in a buffer, but I would like to do the same for demonstrating browser-base and other GUI apps.