ioBroker - flexible and modular application for the IoT and Smarthome
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation
Domoticz - Domoticz is a lightweight Home Automation System
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
FHEM - FHEM (TM) is a GPL'd perl server for house automation.
mediola IQONTROL - A Home Gadget, IoT Hub for multiple devices and vendors