GHuser - Better GitHub profiles for everyone
TLDR pages - The TLDR pages are a community effort to simplify the beloved man pages with practical examples.
Octohunt - Search to find developers in your city on Github.
cheat - Cheat allows you to create and view interactive cheatsheets on the command-line.
GitHub Visualizer - Enter user/repo and see the project visually
CheatKeys - View Windows keyboard shortcuts in the current application.