Eclipse Paho is an open-source project that provides MQTT client libraries for multiple programming languages. It is maintained under the Eclipse Foundation and serves as one of the most widely used MQTT client implementations. Paho supports both MQTT 3.x and 5.0, enabling reliable communication between IoT devices and brokers. Developers use Paho in embedded systems, mobile apps, and backend services. Its flexibility and community support make it a go-to solution for integrating MQTT into IoT projects. With broad adoption, it plays a key role in standardizing MQTT client development.