OpenHAB is an open source automation platform designed to use a pluggable architecture, which means that new devices and protocols can be added easily. This pluggability extends also to the persistence layer, so your system can maintain its state information on your choice of platform
"One thing that immediately impressed me with openHAB was the huge variety of bindings for different devices and services. Virtually every type of home automation hub and protocol is covered; if you have an Insteon-based hub already in place, for instance, openHAB can take over management of the system while using your hub as a communications portal to Insteon and older X-10 devices. Or, if you have aNest thermostat, you can get information from the Nest and use it to configure roller blinds, attic fans, or other HVAC devices. You can even add a contact to a window (which doubles as a security contact) and when the window is open, flip the Nest into "Away" mode. Networkable UPS units, an Asterisk PBX, CalDAV, an assortment of projectors and other multimedia devices, Philips HUE, Wemo, Plex, Z-Wave devices, and a whole lot more—it's all modular. You set up the bindings and application integrations you want, and then you can have events on one thing trigger others. A few enterprising users have even used Amazon Alexa's Home Automation Bridge to add voice control with Amazon Echo and Echo Dot devices."