Gymathtics

I'm looking for open source stuff in Java or Python that solves calculus problems and plots them. It would be cool to see something show the solution by reviewing what little memorized proof or method is required. Then, showing some examples of real world uses with examples would be cool.

While I agree that solving a problem is a pleasure in and of itself, I have say that I think mathematics would be so much more interesting if I could see real world uses and practices for it in everyday living. Practice in math is equal to practice in a foreign language.

The use and application of calculus could be as addictive as a good video game. Maybe that's it. Maybe a little calculus video game could set up situations for characters to use calculus to solve problems at different levels (with and without prompted help).