In this case anon just want to search and replace text in file using various text editors, but he describes it funny way:
Although the relevant links have already been provided, the gist is
Acme doesn't stand for some generic editor! It's the famous acme text editor by Rob Pike. It's an interesting editor, very different from Emacs or Vim, and yes, very mousey. In this video Russ Cox gives a great overview: https://youtu.be/dP1xVpMPn8M
These are text editors. Look up regular expressions. These are hyperbolic descriptions of what it takes to use them in each.
Added Wiki links
you can remap vim to use whatever you'd like instead of esc, or just ditch your caps lock and make that your new escape key.
I know some vim users swear by remapping esc to jh
or similar so you don't even have to leave the home row
Just swap Esc and Caps Lock. More comfy. Plus most people don't even use Caps Lock anyway.
I map caps-lock to escape on short press, caps-lock to ctrl when pressed with another key, and both shifts to caps-lock when pressed together. It's more intuitive than it sounds, trust me.
I wanted to get really good with eMacs, but the price of the foot pedals and steering yoke was prohibitive.