ioBroker - flexible and modular application for the IoT and Smarthome
Domoticz - Domoticz is a lightweight Home Automation System
Home - Securely control all your HomeKit accessories from your favorite iOS device.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Nim Home Assistant (NimHA) - Nim Home Assistant is an open-source home automation platform running on Nim.
Apilio - Automate actions in your smart home with almost any connected device.