OpenHAB

[2] Actions, such as switching on lights, are triggered by rules, voice commands, or controls on the openHAB user interface.

According to Black Duck Open Hub, it is developed by one of the largest open-source teams in the world.

OpenHAB supports a number of persistence backends for storing and querying the smart home data, including relational and time series databases.

[8] After installation, openHAB scans the local network and discovers devices that can be included in the smart home solution.

These "Items" correspond to one specific component like a relay controlling a light, the desired temperature of a heating system or a dimmer percentage.

An event, condition, action rule-based system is used to automate the smart home.

[14] Apart from some technical code changes (e.g. use of Java 11), several functional improvements are foreseen: The main drawback is that backward compatibility to openHAB add-ons for version 1 is dropped.