CodeProject: Solving ordinary differential equations in C++. Free source code and programming help

When I was in college I was neck deep in differential equations. Differential Equations are over math and physics and chemistry. They are used to show how quantities evolve with respect to other quantities. For example position of a point mass with respect to time. I was happy to find an article about how to handle differential equations in C++. The article show how to numerically solve the following equations which give rise to the picture on the left!

d x1 / dt = sigma * ( x2 - x1 )
d x2 / dt = R * x1 - x2 - x1 * x3
d x3 / dt = x1 * x2 - b * x3

Where
sigma = 10
R = 28
b = 8 / 3

CodeProject: Solving ordinary differential equations in C++. Free source code and programming help