Recently, I downloaded eigenMath to play with. It's really neat and ...

>And now you got another one?
Yes. It's an old piece of software, originally called Macsyma, developed in the 1970s at M.I.T. But people are still working on it and it's available here ... and it's free!

>Any good?
Yes, it's absolutely delightful!

>But it's old! Did I mention that people are still working on it? The 5.11.0 version that I downloaded is a Dec, 2006 version. >What good is it to you? You have no idea what I had to do to get this pretty picture, in an earlier tutorial: Now it'll be much easier!

Anyway, here's how you play with it ...
>Wait! Is that the only one available?
Check out this.

Anyway, here's how you play with it:

• Click on the Maxima icon (after it's been installed) and get a window:
  
• Type in some command and hit the Enter key:
  
  and you get:
  
  Note that %i1 and %o1 mean input1 and output1.
• Click on Plot 2D ... and a window pops up:
  
  The % means the last result. In our case, that's the result of integrate(x^3*exp(x),x). You get:
  
• You can change stuff, like this:
  
  where %o1 means output1, namely the result of integrate(x^3*exp(x),x), and you get a window with:
  
  where you can move your cursor and get its coordinates!
• Then you can Plot 3D..., getting a window like so:
  
  and a graph like so:
  

>That's it?
Hardly. You can Plot 3D... choosing "openmath" format, then click on the graph and move it about, like so:

You can also Plot 3D... and choose other formats, clicking on the graph to move it about:

Then, too, you can INPUT: an Ordinary Differential Equation

Hit Enter to see it, then click on , adding the %

See also eigenMath.