A free tech magazine. I don't know how practical the one page per article constraint is, but it is fun and I'm enjoying Issue 8 so far.
ants as enemies in science fiction
A good series on how sensitive accuracy is to various factors of marksmanship (group tightness, consistency of ammo velocity, cartridge selection, wind calls...)
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/