3D Graphics version 2.0 by Jason Melquist
  Graph equations; rotate for perspective.
  March 1997 freeware for math students and
  others who want to visualize equations.
  Easy and powerful under Win3.1/95/NT.

  (v1.34) CurveExpert - Curve Fitting/Plotting
  Comprehensive curve fitting system for 
  Windows.  Linear regression models, nonlinear 
  regression models, interpolation, splines are
  supported.  Over 35 models are built-in; 
  custom regression models may be defined by 
  the user.  Full-featured graphing capability 
  allows thorough examination of the curve fit.     
  Shareware (US$ 35.- MC/Visa/Disc/Amex/Check)      
  Daniel G. Hyams, dhyams@ebicom.net   

  (v4.1) DataFit is a tool to perform nonlinear
  regression (curve fitting) & data plotting. 
  Fit data (up to 9 independent variables) to 
  regression models with up to 20 parameters. 
  Define your own models, or choose from over 
  150 built in 2D/3D models. Results include 2D
  & 3D plots, and a variety of fitting 
  parameters. Export code in BASIC or C to use 
  a model in a user written program. Easily 
  used by both experts & beginners.

  MATH FLIGHT v1.2 for Windows 95 <ASP>
  Practice basic arithmetic with activities
  that include Add,Subtract,Multiply,Divide,
  Mix Add/Subtract, Mix Multiply/Divide or
  Mix-Up. Use and Print arithmetic operation
  tables. 7 difficulty levels. Focus on a
  specific number. Print report cards. Race
  against Timer or Airplane. Print Math Fun
  (test) Papers. Hall of Fame. Youth/Adult
  modes. Sound support. Two new games added.

  SymbMath  by Dr Weiguang Huang -
  A powerful symbolic calculator.  Solves
  mathematical and algebraic problems and
  provides a complete symbolic, numeric
  and graphical computing environment with
  built in expert system, program language,
  database and editor.  Rivals Mathematica.

  Mathomatic V7.8: Symbolic math program
  This program can automatically
  solve, simplify, combine, and graph
  algebraic equations, etc.  Does
  calculus operations, too.  Runs
  under MS-DOS or Windows.