Preplar - A simple assignment organisation app built by a 14 year old
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Sunrise - Sunrise is a service desk management software for organisations, supporting both internal & external customers.
ioBroker - flexible and modular application for the IoT and Smarthome
Storypark - Child Care and Daycare Management and Other Education
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation