Calculus and differential equations
Students - if you want integrals check out http://integrals.wolfram.com/index.jsp or http://www.wolfram.com/products/student/mathforstudents/index.html or just buy a student version of Mathematica http://store.wolfram.com/view/app/timedstudent/annual.str
October 2007 - http://www.wolfram.com/interactivedeployment - Wolfram announces "a new Mathematica development that will change the way you share and deploy documents. Starting this week, our interactive technologies are open to everyone. Almost any dynamic Mathematica notebook can now be converted to run in the free Mathematica Player. All it takes is our new Publish for Player web service.
That means you can use Mathematica to build dynamic applications (often with just a few lines of code) and then deploy or publish them in a matter of seconds--whether or not your end users have Mathematica.
Creating applications couldn't be simpler, and now it's just as easy to share your work with others.
Note that Mathematica notebooks can be exported as tex files, so that's a good way to publish. -- thanks to John Boyd
Learn more at: http://www.wolfram.com/interactivedeployment
Contact us at 1-800-WOLFRAM (or +1-217-398-0700 outside the U.S. and Canada) if you'd like to see firsthand how to get started developing with Mathematica. You can also visit our website to learn how to get started: http://www.wolfram.com/mathematica/experience
Sincerely, The Mathematica Product Team" (end of quote)