The modern web design process - An in-depth guide to the processes behind great websites.
Epilepsy Blocker - Block flashing GIFs that may cause an epileptic seizure
Another Lens - A research tool for conscientious creatives by Airbnb
Colorbox.io - Create accessible color systems 🎨
Design Principles - An open source repository of design principles and methods
Coblis - If you are not suffering from a color vision deficiency it is very hard to imagine how it looks...