Explore the world's largest free knowledge app site, the Wolfram Demonstrations Project, answer a few questions and you could win great prizes such as a copy of the computational supertool Mathematica 8 and gift cards to ThinkGeek. The Wolfram Demonstrations Challenge ends on April 18, 2011 so hurry!

What exactly is a Demonstration? Basically, it's an interactive visualization of a concept. The concepts can come from any area such as math, physics, biology, engineering, finance, sociology, music, or art. As you move a Demonstration's controls, you see a change in its output that helps you understand the concept being shown.

Demonstration Sample:

Learn more About the Wolfram Demonstration Project. The Wolfram Demonstrations Project is part of the family of free online services from Wolfram Research—these include Wolfram|Alpha (the world's first computational knowledge engine) MathWorld, The Wolfram Functions Site, and more.