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.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Domoticz - Domoticz is a lightweight Home Automation System
Home - Securely control all your HomeKit accessories from your favorite iOS device.
Tuya Smart - Tuya Smart is a free to use Lifestyle Application by Tuya Inc.