MyController.org - MyController.org is an IoT automation controller for home, office or any place.
Calaos - Open source home automation
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
MajorDoMo - Looking for DIY Smart Home? Try MajorDoMo! Free and open source software Cross-platform (Linux/Windows)
Domoticz - Domoticz is a lightweight Home Automation System