Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Kano - The educational computer and coding kit for all ages
ioBroker - flexible and modular application for the IoT and Smarthome
Harry Potter Kano Coding Kit - Build a wand. Learn to code. Make magic.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
PictoBlox - Coding for kids: Program robots. Make games. Do much more.