Links

Tools

tinytools.directory - A big categorized collection of tiny software tools.
LÖVE - Amazing Lua game framework.
The Death Generator - Generate authentic screenshots and dialogs from a lot of different games using custom text.
Marginalia Search - Search engine for noncommercial sites.
Bitsy - Make tiny games with ease.

Getting started with the web - MDN Web Docs
MDN Web Docs - Guides and documentation for building websites.
CSS only lightbox - Create one of those pop-up thingys without javascript.
Web Accessibility - Practical and wide ranging guide to making your site accessible.
The Rules of Margin Collapse
Should I use pixels or rems?
How to help someone use a computer
Perfect padding - An Empty Bliss Beyond This World - How to pad your paragraphs responsively.

Wikimedia Commons - Need a free picture of something? They've got it.
Paper Tiles - Free beautiful wallpaper pattern backgrounds.
Betty's Graphics - A massive hand curated archive of free graphics.
Use and Modify - A huge hand curated selection of good free fonts.
The Ultimate Oldschool PC Font Pack
Art Bits from HyperCard - Archive of one bit clipart from Hypercard.
Lospec palette list - User made pixel art oriented colour palettes (lots of 'em).
Easing Functions Cheat Sheet
BBC Sound Effects - Free sound effects from the BBC's archive.

Transparency boo - Delightful video essays. They mostly do art analysis on video games.
Hames Joffman - Premium quality YTPs remixing James Hoffman's videos about coffee.
Song that plays when you encounter a caterpillar
Camille - Surreal, existential, awkward commedy skits. Try "Elevator trivia".
Nina Simone - My Baby Just Cares For Me - With a stylish claymation music video. This is very good.

What Football Will Look Like in the Future - A fascinating, heartwarming, silly, sometimes mysterious piece of mixed media fiction (that's what it's been like so far, I'm not that far into it). No knowledge nor interest in football (any kind) required.
Dinosaur Comics - Silly, fun, optimistic webcomic.