- Topology articles from Eric Weisstein's
*World of Mathematics*, sponsored by wolfram.com. - Geometry/topology section of Mathematical Atlas, coordinated by Dave Rusin (Northern Illinois Univ)
- What is topology?, by Bob Bruner (Wayne State Univ)
- What is algebraic topology?, by Joe Neisendorfer (Univ of Rochester)
- What is topology? , by Neil Strickland (Univ of Sheffield)
- Encyclopedia article about topology, by Don Davis (Lehigh Univ)
- What is Topology (intro to course), by Zbigniew Fiedorowicz (Ohio State Univ)
- What is topology, by Kevin Iga (Pepperdine Univ)
- History of Topology (early years), from St Andrews Univ History of Math archive.
- Algebraic topology entry in Wikipedia (online encyclopedia)
- New York Times essay by Steven Strogatz about singularities.
- What is Topology page by Jerrold Siegel.
- Oxford Mathematical Institute answer to What is Topology?
- A History of Algebraic Topology by John McCleary (Vassar College).

- Higher dimensional group theory, by Ronald Brown (Univ of Wales, Bangor)
- Knot Theory,