Topology

Algebraic Topology Discussion List
The primary functions of this list are: providing abstracts of papers posted to the Hopf archive, providing information about topology conferences, and serving as a forum for topics related to algebraic topology. The site also serves as an archive of links to websites related to algebraic topology.
http://www.lehigh.edu/~dmd1/algtop.html

British Topology Home Page
A source of pointers to Topology-related sites, including archives and conference announcements.
http://www.maths.gla.ac.uk/~ajb/btop.html

The Cantor Set
Article in the Platonic Realms, describing the Cantor discontinuum, a favorite example of topology. Includes examples and illustrations.
http://www.mathacademy.com/pr/prime/articles/cantset/

Differentiable manifolds
Lecture notes by Mariusz Wodzicki in postscript or pdf.
http://math.berkeley.edu/~wodzicki/214/

Differential Topology
Course notes by Matthew G. Brin in PostScript including "Introduction to Differential Topology", "Introduction to Seifert fibered 3-manifolds", "Groups acting on 1-dimensional spaces", and "Presentations, conjugacy, roots and centralizers in groups of piecewise linear homeomorphisms of the real line".
http://www.math.binghamton.edu/matt/

Links to Low-dimensional Topology
Topics: General, Conferences, Pages of Links, Knot Theory, 3-manifolds, Journals.
http://www.math.unl.edu/~mbrittenham2/ldt/ldt.html

MAA Basic Library List in Topology
MAA recommended books in General, Geometric, Algebraic and Differential Topology.
http://www.maa.org/BLL/topology.htm

Mazes and Mathematics
History and mathematical analysis of labyrinths.
http://www.math.sunysb.edu/~tony/mazes/

Planar Machines - an Invitation to Topology.
Java applets exploring configuration spaces.
http://www.math.toronto.edu/~drorbn/People/Eldar/thesis/index.html

Topics in Mathematics - Topology
In the Mathematics Archives at University of Tennessee, Knoxville.
http://archives.math.utk.edu/topics/topology.html

Topology
Descriptions and illustrations of several topological and differential geometry related notions.
http://www.chez.com/alcochet/toposi.htm

Topology Atlas
Preprints, abstracts, calendar, links, other resources.
http://at.yorku.ca/topology/

Topology Course Lecture Notes
By Aisling McCluskey and Brian McMaster. HTML with symbol fonts, DVI and PostScript.
http://at.yorku.ca/i/a/a/b/23.htm

Topology Glossary
Definitions of over 100 terms in topology.
http://www.ornl.gov/sci/ortep/topology/defs.txt

TTT on WWW
The Transpennine Topology Triangle is a topology seminar partially supported by the London Mathematical Society with vertices at Leicester, Manchester and Sheffield.
http://www.greenlees.staff.shef.ac.uk/ttt/ttt.html

What is Topology?
An introductory essay by Neil Strickland, University of Sheffield.
http://neil-strickland.staff.shef.ac.uk/Wurble.html