Larry McVoy on 30.12.2022 21:02:

> > [SysIII port]
> Is there are reason to hang on to the Bourne shell?  Maybe shell scripts?
> Does it perform better than ksh or bash?
>
> Don't get me wrong, I much prefer the sh syntax over csh syntax, but
> I'd never go back to the Bourne shell as my login shell.  Way too much
> useful stuff in ksh/bash.

I'd like the idea of   "preserving a heirloom in its natural environment"
(and even more effort went in https://heirloom.sourceforge.net/sh.html)
let alone this does not prevent from adding modern shells...

I guess in interactive use most users would only miss one thing: the 
history & line editing capability?

Side notes to that:

  * By intention, the almquist shell (a port due to the Berkeley/ATT
    mess) initially had no history. From the package file DIFFERENCES [1],

    "History.   It seems to me that the csh history mechanism is mostly
    a response to the deficiencies of UNIX terminal I/O. Those of you
    running 4.2 BSD should try out atty (which I am posting to the net
    at the same time as ash) and see if you still want history."

  * and in "ksh - An Extensible High Level Language" David Korn writes:

    "Originally the idea of adding command line editing to ksh was
    rejected in the hope that line editing would move into the terminal
    driver." [2]

I have always wondered, what such a central terminal driver driven 
history/line-editing would have felt like.

[1] https://www.in-ulm.de/~mascheck/various/ash/DIFFERENCES
[2] https://www.in-ulm.de/~mascheck/bourne/korn.html