WinWedge - Data collection software for serial devices, including meters, balances, scales or any RS232...
FHEM - FHEM (TM) is a GPL'd perl server for house automation.
TWedge - TWedge enables you to capture data from devices like bar code readers, scanners, decoders, gauges...
Homebridge.io - Homebridge is a lightweight NodeJS server you can run on your network that emulates the iOS HomeKit...
NoFlo - NoFlo is a JavaScript implementation of Flow-Based Programming (FBP).
Conrad Connect - Service for managing smart home devices