Wolfram MathWorld
https://mathworld.wolfram.com/The web's most extensive mathematics resource, featuring 13,000+ entries, interactive examples, and detailed geometric illustrations.
Features: Wolfram MathWorld is the web's most extensive and authoritative mathematics resource, boasting over 13,000 highly detailed entries. It features comprehensive coverage of topics ranging from algebra and geometry to calculus and topology. The site is enriched with interactive examples, sophisticated mathematical derivations, clear geometric illustrations, and links to the Wolfram Language, allowing users to visualize complex concepts and perform computational experiments directly.
History: Originally created by Eric W. Weisstein in 1995 as the "Treasure Trove of Mathematics," the site was later acquired and hosted by Wolfram Research. It was designed to serve as a comprehensive, searchable encyclopedia of mathematics, maintaining rigorous academic standards while becoming a staple for researchers, educators, and students worldwide.
Use cases: MathWorld is an essential tool for university students and academics looking to verify mathematical definitions, explore advanced proofs, or reference specific theorems. It is also widely used by educators to supplement lesson plans with high-quality illustrations and by hobbyists to explore complex mathematical recreations and patterns.