Behavioural Calculus by Orfeo Bernardo: Behavioural Calculus with Analytical and Visual 3 Space for Windows. Promotional freeware is available.
Calculus Made Easy for the Ti89/Titanium/Ti-92+/Voyage200: Collection of subprograms and menus that will help the user solve calculus problems and recall useful theorems, definitions, and rules.
GraphFunc: GraphFunc is a program online that is used to plot the graph of mathematical functions in two or three coordinate systems. You need Java Runtime Environment to use this site.
SID2002 Math Expert System: Solves problems and shows step by step solution using artficial intelligence.
The Integrator: An online integrator that automatically evaluates integrals.