~ Early Web Links ~

The Geometry Center was a University of Minnesota research and education hub dedicated to mathematics, geometry, and visualization tools, now archived after its closure. Visitors can explore interactive Java applications, 3D geometry software like Geomview and JGV, multimedia math documents, downloadable software, and video productions covering topics from solar system models to symmetry exploration.

A curated collection of mathematics education links compiled at Andrews University, organized into sections for teachers, parents, and students across K-12 grade levels. The directory covers lesson plans, interactive activities, problem-solving resources, and NCTM-aligned curriculum materials from across the early web.

PlanetMath.org is a collaboratively built mathematics encyclopedia where community members write and review entries covering a vast range of mathematical topics, all rendered in LaTeX. Hosted by the University of Waterloo and operated as a nonprofit, it offers both a subject index and alphabetical index, making it a serious reference hub for students, educators, and math enthusiasts.

Dominic Cook's personal site collects his explorations in mathematics, number theory, measure theory, and speculative metaphysics alongside creative web projects like 88x31 webpins, glitch art, and calculators. The mix of rigorous mathematical writing and old-web aesthetics makes it a quirky, intellectually curious corner of the indie web.

Created by Alexander Bogomolny starting in 1996, Cut the Knot is a massive encyclopedic collection of interactive mathematics covering geometry, algebra, probability, puzzles, proofs, and much more, built over decades until his passing in 2018. With thousands of pages, interactive Java applets, Olympiad problems, and articles spanning all levels of math, it stands as one of the most beloved and comprehensive math resources ever built on the early web.

David E. Joyce of Clark University presents a detailed mathematical exploration of compass-only geometric constructions, proving that a straightedge is unnecessary for any Euclidean construction. The site covers circle inversion, stereographic projection, inversive geometry, and involutory quandles, drawing on the historical work of Mohr and Mascheroni.

The National Curve Bank is a mathematical archive dedicated to cataloging and exploring curves, offering detailed information on their properties, equations, and historical significance. A sister site to the Witch of Agnesi page, this project serves as an educational reference for students, educators, and math enthusiasts interested in the geometry of curves.

Math2.org is a comprehensive math reference site offering organized tables, formulas, and identities covering everything from basic arithmetic to calculus, linear algebra, and Fourier transforms. Available in both English and Spanish, it also features a message board for math questions and links to other top math resources on the web.

Pi Land is Eve Andersson's comprehensive tribute to the mathematical constant pi, featuring trivia games, a memory trainer, digit search tools, frequency analysis, and multiple calculation methods including Gregory-Leibniz and Monte Carlo. The site blends nerdy exploration with aesthetic touches like poetry, photos, and art, making it a delightful destination for math enthusiasts of all levels.

Christian Plesner Hansen's technical blog dives deep into the legendary fast inverse square root hack and its magic constant 0x5f3759df, tracing the algorithm's surprising history from Ardent Computer in the 1980s through SGI, 3dfx, and Quake III Arena. The post rigorously explains the underlying floating-point bit manipulation, generalizes the technique to arbitrary powers, and includes graphs and mathematical derivations that illuminate why this 'evil' hack actually works.