ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Mycroft.AI - Mycroft is the world’s first open source assistant.
ioBroker - flexible and modular application for the IoT and Smarthome
Google Assistant - Get things done with Google Assistant
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation