openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Tuya Smart - Tuya Smart is a free to use Lifestyle Application by Tuya Inc.
ioBroker - flexible and modular application for the IoT and Smarthome
Geeni - Geeni is a powerful tool that controls all Geeni smart home devices using a single, easy to understand app.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Domoticz - Domoticz is a lightweight Home Automation System