In this case anon just want to search and replace text in file using various text editors, but he describes it funny way:

• acme: very slow process because it requires using mouse and keyboard alternately
• emacs: faster because you don’t have to use mouse but requires pressing a lot of weird and complicated key combinations and use many modifier keys like ctrl, alt and so on, in this case description is a bit exaggerated. Also see emacs pinky syndrome
• vim: portrayed as simple and efficient, anon is probably vim user.

Although the relevant links have already been provided, the gist is

• Acme stands for some “generic” editor here, where you have to use the mouse a lot, which is perceived as slow
• Emacs is known to be very powerful (to the extend of being called an “OS with a bad editor”), but using unergonomic keyboard shortcuts
• Vim is an editor that has been designed for keyboard power users in mind, but which has the reputation of being difficult to learn

These are text editors. Look up regular expressions. These are hyperbolic descriptions of what it takes to use them in each.

Added Wiki links

acme

emacs

vim