Here I offer my Mathematica notebooks and packages presenting some special subjects in algebra, analytic and differential geometry. I tried to give systematic presentations with enough explaining text. The most important contain enhancements of Mathematica to handle problems in pseudo-Euclidean, symplectic, and Moebius geometry. Some are updates of my old submissions to MathSource, and some smaller discuss problems I met working with Mathematica. On the following URL you may get detailed information and download the stuff:
I would be very grateful about any echoes, critiques, or advice concerning the use of the material.