[joshcorbin]

Isn't it a bit of a retcon to say that Vi(m) has grep builtin?

As far as I understand it, grep was named for the :g/.../p sequence one can do with Vi's global command; that is "global-regex-print".

[drcube]

"grep" came from ed: g/re/p "global regex print".

It's much older than vi (1976 vs 1973):

http://en.wikipedia.org/wiki/Grep

[mgedmin]

There's also :vimgrep

I believe it's more useful on Windows machines, which for some reason usually come without preinstalled grep.