jkl Wrote:It's not everywhere. You either don't even have a vi command (e.g. on Gentoo) or end up with Vim or nvi symlinked as "vi", both of which are very different applications.

I'd be surprised if the Gentoo install media didn't include vi! Though the handbook indeed mention nano as the editor.
Anyway, busibox vi, nvi and vim are different from Bill Joy's original vi, but they are still compatible with it, so they still qualify as valid replacements to me!

jkl Wrote:I recently came across a Linux that didn't even have ed, I think it was CentOS.

Yeah that is insane right? I discovered that after fucking up with termios so I couldn't use ncurse properly... That pissed me off!
I think ubuntu ditched it as well.

jkl Wrote:Better don't assume anything to be available anywhere at all.

Fair enough! Still, I think you will be more likely to find vi than emacs on most setups!