I now have all of the above programs ($$$!), and have started a comparison review.  It's a bit like comparing Euler, Euclid, and Einstein.  Each of the above links will take you to the corresponding home page for these programs.  As a starter, I graphed sin(x sin(y)) = cos(y cos(x)).  The results are beautiful.  Mathematica's graph.  Maple's graph. Nucalc's graph.  GrafEQ's graph.  Can Mathcad do this?  I will have much more on these programs in the months to come.  If you know of other mathematical software programs, please contact me.