FHEM - FHEM (TM) is a GPL'd perl server for house automation.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Conrad Connect - Service for managing smart home devices
Google Home - Set up, manage, and control your Chromecast, Chromecast Audio and Google Home devices.
ioBroker - flexible and modular application for the IoT and Smarthome
pimatic - Home automation framework that runs on node.js.