FHEM - FHEM (TM) is a GPL'd perl server for house automation.
PiDome.org - PiDome is the Home Automation Platform for the Raspberry Pi containing a server, multiple clients with user friendly interfaces
Conrad Connect - Service for managing smart home devices
MyController.org - MyController.org is an IoT automation controller for home, office or any place.
Homebridge.io - Homebridge is a lightweight NodeJS server you can run on your network that emulates the iOS HomeKit...
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.