ioBroker - flexible and modular application for the IoT and Smarthome
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
IP-Symcon - IP-Symcon is the innovative centre of your entire building automation!
Home - Securely control all your HomeKit accessories from your favorite iOS device.
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Nim Home Assistant (NimHA) - Nim Home Assistant is an open-source home automation platform running on Nim.