Group theory entering quantum physics is a particularly funny example, because some established physicists at the time really hated the purely academic nature of group theory that made it difficult to learn.[1]

If you include practical applications inside computers and not just the physical reality, then Galois theory is the most often cited example. Galois himself was long dead when people figured out that his mathematical framework was useful for cryptography.

[1] https://hsm.stackexchange.com/questions/170/how-did-group-th...

> When I run 'notepad dir1/file1.txt', the package should not sneakily be able to access dir2.

What happens if the user presses ^O, expecting a file open dialog that could navigate to other directories? Would the dialog be somehow integrated to the OS and run with higher permissions, and then notepad is given permissions to the other directory that the user selects?

Thanks for sharing this! Went and changed some keybinds right away.

My favourite feature is userChrome. The default chrome sucks in both Chrome and Firefox, but at least Firefox allows me to customize it to my liking without forking the entire browser.

On the flip side, changing keybinds in Firefox requires forking, but the defaults aren't too bad.