HomeRun for HomeKit - HomeKit actions on your wrist
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Gizmote - Remotely control & manage your Android devices in the cloud
ioBroker - flexible and modular application for the IoT and Smarthome
ICON Home - 3D printed housing in 24 hours
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation