VI (1976) → VIM (1991): A REAL, TINY EMULATOR

vi was written by Bill Joy in 1976 for BSD Unix, for a world of slow serial terminals where every keystroke sent over the wire was expensive — hence a language of single-letter commands and no menus. Vim ("Vi IMproved") followed in 1991 and is still, thirty-plus years later, what half the internet's servers get edited with over SSH. The best way to learn it isn't to read about it — it's to type into it. Below is a small but real modal editor, implemented in JavaScript, with six guided lessons.

Lesson

NORMAL

Click the black terminal above, then type. It captures your keyboard the way a real terminal window would — click elsewhere (or press Esc then Tab) to escape it.

CHEAT SHEET (what this emulator supports)

Key(s)	Mode	Effect
`h` `j` `k` `l`	Normal	move left / down / up / right
`0` / `$`	Normal	jump to start / end of line
`gg` / `G`	Normal	jump to first / last line
`i` / `a`	Normal	insert before / after cursor → INSERT mode
`I` / `A`	Normal	insert at start / end of line
`o` / `O`	Normal	open new line below / above → INSERT mode
`x`	Normal	delete the character under the cursor
`dd`	Normal	delete (cut) the current line
`yy`	Normal	yank (copy) the current line
`p`	Normal	paste after the current line
`V`	Normal	enter VISUAL LINE mode (select whole lines with j/k)
`d` / `y`	Visual line	delete / yank the selected lines
`Esc`	Insert / Visual	back to NORMAL mode
`:`	Normal	enter COMMAND-LINE mode (bottom of screen)
`:w` `:q` `:wq`	Command-line	write / quit / write-and-quit (simulated)