Applied/Computational topology resources

• Eirene -- state of the art Julia code, returns generators for giant complexes!
• Ripser - browser based persistent homology computations
• Perseus
• CHomP
• Dionysus
• Rob Ghrist's Elementary Applied Topology

Useful programming languages

• Julia -- high performance technical computing, and my language of choice
• Sage -- open source mathematics software package

Algebraic topology resources

• Algebraic Topology conference list
• The Knot Atlas
• Allen Hatcher's home page

Math resources

• MIT Open Courseware in Mathematics
• WeBWorK -- open source online homework package
• Wolfram Alpha -- browser based "knowledge engine"
• Math Overflow -- a research forum for mathematicians
• TeX the World -- browser plugin for embedding TeX in documents
• Mathematics on the ArXiv

Math visualization

• Roots of polynomials with integer coefficients
• Jeff Weeks' Topology and Geometry Software -- "Curved Spaces" is must-see.
• KnotPlot
• Mobius Transformations Revealed
• Dynamical Systems and Technology Project
• "The Optiverse" and Other Sphere Eversions
• Thomas Banchoff's Home Page -- check out online projects and artwork

Cool science things

• Waves in a Large Free Sphere of Water
• Things, but very slowly

Math (and science) culture

• XKCD
• Jonathan Coulton
• Klein Four Group -- page seems abandoned
• Andrew Lipson's Mathematical LEGO Sculptures
• ACME Klein Bottles

Math/Science blogs I (sometimes) read

• This Week's Finds in Mathematical Physics
• The n-Category Cafe
• The Secret Blogging Seminar
• Physical Thought

Math community

• The American Mathematical Society
• The Mathematical Association of America
• Pacific Northwest Section of the MAA
• Project NExT
• The Association for Women in Mathematics
• The Young Mathematicians' Network
• The Society for Industrial and Applied Mathematics

Departments where I have (formally) spent time

• University of Nebraska -- Lincoln Department of Mathematics
• Willamette University Mathematics Department
• University of Oregon Department of Mathematics

Non-Math/Science links

• Board Game Geek