On MacOS, the Alt key allows us to generate Unicode chars via regular keystrokes. For example Alt+J → ∆ (Increment, U+2206).
Is there a way to alter my Ubuntu machine so that the Alt key does this?
Currently the Alt key doesn't seem to do anything when combined with letters.
You can use the "English (Macintosh)" layout instead of the standard English layout. Here's how it looks:
You'll need to use the "level 3 select key" (which is usually AltGr aka right-Alt key) to get those characters. For example, to get "∆" you need to press AltGr+j and to get "½" you need to press Shift+AltGr+j.