Vectors are a very important mathematical concept and are often used in basic engineering science courses such as statics and dynamics. Paul Kirby is the creator of Vectorland, an online course that explains three dimensional vector analysis. The material presented on the site covers many topics, like dot and cross products, vector equations of lines and planes, shortest distance calculations, and parametric curves. After completing all the lessons, there are four challenges to test your knowledge. These include a few Java applets that are very difficult to use; fortunately, they are not required for the challenges.