GeoGebra is a free software package combining dynamic geometry, algebra and calculus. You can use it in a lab environment, or for teacher-led classroom demonstrations.  It can be used as a standalone system, or you can create interactive web pages for student exploration outside of class.  Version 4 of this versatile software makes creating interactive demos easier than ever! Try out its interactive features in the Riemann sum mini-applet at the right, or by clicking on the following links:

• The graph of the derivative

• Riemann sums (more general version)
  
  
• Fitting a catenary to a hanging chain
  


• Newton's Method
  
  
• Limits via epsilon-delta

Are you sold?  Can't wait to start creating your own applets?  Click here for links to additional resources, and for copies of the files we used in our presentation.