VerneMQ (.5k)

Scales horizontally and vertically on commodity hardware, supporting high concurrency and fault tolerance for massive IoT deployments, as highlighted in the key features.

Implements MQTT 5.0 with all features like enhanced authentication, message expiration, and topic aliases, ensuring compliance with the latest protocol standards.

Supports plugins for authentication with databases like MongoDB, Redis, and PostgreSQL, allowing seamless integration into existing IoT platforms.

Includes $SYS tree, Graphite reporting, HTTP API, and a cluster status web page for real-time monitoring and administration, as detailed in the features.