What is the Korn shell?

[Paul Fuqua]

     Forgive my ignorance, but what exactly is the Korn shell?  From the
messages I've seen, I know that is more sh-like than csh, that it has
its own history stuff, that it has emacs-like and vi-like line-editing
modes, and that it may be faster than csh.
     The thing is, I use tcsh, and I have all that (emacs-like)
line-editing stuff, plus ^N and ^P to walk up and down the history
visibly, plus completion of a sort (not as good as tops20), and I can
customise the keys to some extent.
     Can someone give me an overview of ksh and compare it to tcsh or
the "new" (completing) csh?  Thanks.

                              pf

Paul Fuqua
Texas Instruments Computer Science Center, Dallas, Texas
CSNet:  pf at csc.ti.com (ARPA too, eventually)
UUCP:   {smu, texsun, im4u, rice}!ti-csl!pf