MyController.org - MyController.org is an IoT automation controller for home, office or any place.
OpenMotics - OpenMotics makes building automation relevant by increasing the comfort of residents while optimising energy management.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Homebridge.io - Homebridge is a lightweight NodeJS server you can run on your network that emulates the iOS HomeKit...
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Calaos - Open source home automation