tom7's videos and SIGBOVIK papers are treasures
Tic-Tac-Toe in static HTML
As seen by Bob Hearn (in 2003)
I bought John Langdon's book Wordplay years ago, but a recent discussion on hacker news reminded me of ambigrams
Graphing calculator emulators on the Internet Archive.
Very nice online gif editor/convertor
"This is a list of things you’re allowed to do that you thought you couldn’t, or didn’t even know you could."
I like these link aggregators by Peter Krumins. Also:
https://mathurls.com/
https://hwurls.com/
https://techurls.com/
https://tuxurls.com/
This is a large collection of single purpose, chainable (like a pipeline) tools for text and image processing (csv conversion, etc) and other tools that are written in javascript and run in the browser. I'm impressed whenever I come across one of them (and they've been useful to me a few times).
"Thinking meat! You're asking me to believe in thinking meat!"
Useful web tools for converting ascii to various Unicode representations.
This website finds the best (so far: WiFi, sex, and the sun) and worst (so far: transaction fees, advertising, mortgage) things using the Glicko2 rating system.