I knew&forgot: .el allowing eg more, less (vi? top?) in *shell*

[David Combs]

1: What's the name of that .../lisp/xxx.el that allows you
to run eg more, less, and other cursor-jumping programs
within *shell*?

(Had a short name, 3 or 4 chars long.)

2: before I try it and get hung or something, what
   about running eg vi, top, etc there too?

   (Hell, what about running another EMACS within *shell*!)

3: This xxx.el -- is it the only, or the best, of such modules?



Thanks!

David