openHAB

openHAB is a free and open-source home automation platform designed to integrate devices and technologies from different brands into a single, coherent system. It runs on a variety of platforms, including Linux, Windows, macOS, and compact devices like the Raspberry Pi, and is implemented in Java, allowing it to be extended and deployed in many environments.

The software uses a modular architecture based on the open source Eclipse SmartHome heritage. Core concepts include Things, Items, and Rules. Bindings connect to devices or services and expose their capabilities as Things with Channels. Items hold the current state of data points and can be linked to Channels. The Rule engine allows users to describe automations in a dedicated language or scripts, enabling actions in response to changes in Items or external events. The system also supports persistence, transformations, and UIs.

Bindings and an extensive ecosystem enable support for hundreds of devices and protocols, such as Z-Wave, Zigbee, KNX, MQTT, HTTP APIs, and more. This vendor-neutral approach lets users build an integrated smart home without committing to a single manufacturer's ecosystem. The user interface includes Main UI, Basic UI, and HABPanel for dashboards, with configuration and rules often managed through a web interface or through text files, depending on version.

History and community: openHAB originated around 2010 and has since evolved through major releases (openHAB 1, openHAB 2, and openHAB 3). It is maintained by a global community and supported by the openHAB Foundation. Official documentation, community bindings, and tutorials are available, and tools such as openHABian provide an easy installer for Raspberry Pi deployments.

See also: Home automation platforms. The project emphasizes interoperability and portability, making it a popular choice for DIY smart homes seeking vendor neutrality and extensibility.