SmallDevTools - Handy developer tools with a delightful interface
Startup Stash - A curated directory of 400 resources & tools for startups
Google Open Source - All of Googles open source projects under a single umbrella
ProppyJS - Functional props composition for UI components (React & Vue)
whatdevsneed - This is whatdevsneed.
Devhints - TL;DR for developer documentation