Why is everyone talking about MQTT?

The Ably platform has recently added official support for the MQTT protocol through their [MQTT gateway](https://www.ably.io/adapters). MQTT, or Message Queuing Telemetry Transport, is a network protocol designed specifically to enable efficient communication between Internet of Things (IoT) devices. Unlike HTTP, it uses the publish/subscribe paradigm instead of request/response for communication. In this model, all clients are either publishers or subscribers, or both, and there's a central entity that manages message routing from publishers to the correct subscribers. This central entity is called an MQTT broker in Ably terminology. MQTT has three main entities: publishers, who push data/messages to the broker; subscribers, who inform the broker of their interest in a certain kind of data and receive it when available; and the broker itself, which ensures correct routing of messages published by publishers to the appropriate subscriber(s). Topics are used as naming specific sets of data. Ably's MQTT Protocol Adapter serves as an internal translation layer that translates client-side endpoints intended to connect with a third-party protocol into one compatible with Ably. This allows for seamless integration between Ably and other platforms or services using the MQTT protocol. Compared to WebSockets, which is widely used in realtime technology, MQTT caters specifically to low bandwidth scenarios and implements the Pub/Sub messaging pattern at the protocol level. It also ensures efficient communication while minimizing battery consumption on hardware devices, making it ideal for use with IoT devices. To set up Ably's MQTT Protocol Adapter, users can follow the steps outlined in the documentation or try out a tutorial that demonstrates building a classic game of Snake using MQTT. When using the MQTT adapter, it is recommended to use token authentication for security purposes, especially when dealing with IoT devices or client-side applications where API keys may be exposed.