Source : Free On-Line Dictionary of Computing

[incr Tcl]
     
         An extension of {Tcl} that adds {classes} and
        {inheritence}.
     
        The name is a pun on {C++} - an {object-oriented} extension of
        {C} - [incr variable] is the Tcl {syntax} for adding one to a
        variable.
     
        [Origin?  Availability?]
     
        (1998-11-27)