(I lost the answer) How to run vi,Lynx,etc within emacs window?

[David Combs]

I asked this question some years ago, and thought
I saved the answer, but I can't find it.

There was some mode I could run, which would let me
run a cursor-jumping program like vi or lynx from
within emacs.  But I don't remember what it was,
nor can I find it in my notes.

And google: I don't even know what to search for.

So I'm asking you.

THANKS!

David