Software projects:

- Calculus Wars. Serious games for calculus teaching.
- plCurve. Fast library for polygons in C and Python.
- octrope. Fast computation of polygonal thickness in C.
- tsnnls. Sparse, non-negative least squares solver.
- vecttools. Utilities for geometric computations on polygons.
- ridgerunner. Knot tightening software.
- Perl Encyclopedia of Triangle Centers. All the triangle centers you could ever want. In Perl!