Answers and Explanations - This area is designed to be a place where you can delve more deeply into some foundational questions in mathematics, and find expositions on some topics that often seem puzzling when glimpsed from a distance.
The Kenzo program. - A computer program for computational algebraic topology.
The QED Project - Home Page - The aim of the QED project is to build a single, distributed, computerized repository that rigorously represents all important, established mathematical knowledge.
Question Corner - A place for high-school students and others to ask questions about mathematical topics and receive accurate and informative answers. No longer active, but old questions and answers are archived.