Here is a haphazard collection of other things I have done. These include various math and quizbowl writings, and smaller coding projects.
Besides HTML/CSS, Perl, and PHP, I am fluent in LaTeX, a professional typesetting language that allows for easy formatting of articles and books, especially for mathematics. It is used by the American Mathematical Society and many other mathematical organizations. Many of my writings were produced with LaTeX.
On my website
MV Suite: I wrote a formula sheet for multivariable calculus (Calc III and IV) and a set of nine functions for the TI-89, which automates several simple formulae. They can calculate the TNB frame, gradients, div, curl, curvature, and the center of mass of a simple planar lamina.
Linear Transformations: I also wrote a set of lecture handouts for a week-long set of lectures I gave in math class at the end of my senior year of high school. They attempt to quickly review our computational study of matrices, while presenting the material in a very conceptual way based on linear transformations.
Monday Mathematics: This is a series of (very) infrequent essays that address different common problems in mathematics and the simple but elegant math behind solving them.
Elsewhere
Tropic of Calculus: I have contributed multivariable calculus lessons to this project started and maintained by my friend Jonah Greenthal.
Much Ado About Quizbowl: I contribute to Aegis Questions's blog, run by its directors, who discuss all things quizbowl-related.