If you want to play with the winding number proof of the fundamental theorem of algebra, here's a toy I made a while back to help my linear algebra students (ho

If you want to play with the winding number proof of the fundamental theorem of algebra, here's a toy I made a while back to help my linear algebra students (hopefully) gain some intuition for complex numbers: https://math.berkeley.edu/~kmill/toys/roots/roots.html https://math.berkeley.edu/~kmill/toys/roots/roots.html If you want to play with a wider palette of complex functions as well as domain coloring of the Riemann sphere, there is also https://math.berkeley.edu/~kmill/toys/zgraph/zgraph.html https://math.berkeley.edu/~kmill/toys/zgraph/zgraph.html Documentation for each of them is the "Help" link in their respective upper right corners. One thing I think would be amusing is to be able to change the texture used for the domain coloring, from the contoured rainbow to say a cat.