[pmccool]

> There are a very few it is not included in, but these do not have any other editors either.

I'm curious: when have you come across an editor-less unix?The vi-less ones I've come across have generally had some bizarre substitute that uses wordstar keystrokes or something equally obscure...

You raise a fair point, though: knowledge of vi = knowledge of ed which will work even when vi won't (horrid slow link and/or broken terminal emulation).

[gvb]

I've come across ones with only "ed", but the last time I had that was 20-odd years ago. I would counter all unix (like) operating systems have an editor because I've never run across one without "ed" (and "sed").

[sliverstorm]

most commonly rescue or pre-boot environments. A rescue environment without a text editor is severely hampered, it's true, but sometimes things other than config files need rescuing, and floppies are small.