How about a large "toolbar" window?
When an operation is needed, the toolbar window pops up with a key press.
Remember, many software have a quick reference card of one or two pages.
One could typeset the card in the toolbar window (possibly multiple pages)
and add transparent buttons over it. No patent pending.
The toolbar window has always the operations typeset at the same
locations if so wanted. That is the second plus over the deep menus
which have no fixed layout between the menu windows.
BTW, the emacs style command system was also a good idea.
E.g., "Esc x filters-noise-spread" and "ctrl-x n s".
Emacs also has the command apropos something which helps in finding
the suitable commands.
for developers of open source graphics software
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