ioBroker - flexible and modular application for the IoT and Smarthome
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Gladys - An open-source home assistant powered by a Raspberry Pi 🗣️
Domoticz - Domoticz is a lightweight Home Automation System
SmartRent - Smart home automation for property managers and renters
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation