Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Lexi - Speak to Alexa through your iPhone
ioBroker - flexible and modular application for the IoT and Smarthome
Astra by Cesbo - Talk to Alexa anywhere, from your iPhone
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Ava - Making conversations accessible for the deaf