Source : Free On-Line Dictionary of Computing

C shell
     
         (csh) The {Unix} {command-line interpreter}
        {shell} and {script language} by {William Joy}, originating
        from {Berkeley} {Unix}.
     
        {Unix} systems up to around {Unix Version 7} only had one
        shell - the {Bourne shell}, sh.  Csh had better {interactive}
        features, notably command input {history}, allowing earlier
        commands to be recalled and edited (though it was still not as
        good as the {VMS} equivalent of the time).
     
        Presumably, csh's {C}-like {syntax} was intended to endear it
        to programmers but sadly it lacks some {sh} features which are
        useful for writing {shell scripts} so you need to know two
        different syntaxes for every shell construct.
     
        A plethora of different shells followed csh, e.g. {tcsh},
        {ksh}, {bash}, {rc}, but sh and csh are the only ones which
        are provided with most versions of Unix.
     
        (1998-04-04)