Hackable-devices : The hackable-devices project is coming from the willingness to make available to hackers and makers materials that correspond to them. Much more than ...
Hack a Day : Hackaday serves up Fresh Hacks Every Day from around the Internet.
Feather : Feather is a collection of simple open source icons. Each icon is designed on a 24x24 grid with an emphasis on simplicity, consistency and readability...
Fun Retro : Easy to use and beautiful restrospective board.
Zulip : Powerful slack-like open source group chat
Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists and anyone interested in creating interactive objects or environments.