• Try the nonlinear programming demo! You can choose from a list of available nonlinear models, select one of five different solvers, and set your own starting point. The solution trajectory is then shown on a contour plot. This requires downloading a zip file, unpacking it, and installing the software.  The demo and installation instructions are here. Software developed by Jennifer Pryor.

• The Steepest Descent Method is a classic method for solving NLP minimization problems. There is a great online demo here.

• Other optimization related animations are available here.