Just wanted to share the news that the RabbitMQ team have worked hard on a RabbitMQ adapter for MQTT. This means that a RabbitMQ broker can now act as an MQTT broker and also interchange between AMQP and MQTT. The code is available on Github
with an extensive blog post about the capabilities from Emile on the RabbitMQ blog
Do try it out and let the team know what you think! There are RabbitMQ package for many OSes and hopefully the MQTT adapter can start to be bundled with those in the future.
To go along with this new implementation, I've started to work on improving the Server capabilities page on the MQTT.org wiki to get better information about what the different MQTT brokers can do.
I know there are a couple of others to add there, like the MQTT.js broker, and I'd appreciate any help in filling in the blanks, too.
All of this, and some of the spec questions that have come up lately, point (again!) to the need to work together on:
a) cleaning up and clarifying the v3.1 spec - I guess this is something that IBM and/or Eclipse Paho need to republish in a new revision;
b) a protocol test suite that we can use to check brokers - I know mosquitto ships with a number of tests, and it would be good to see something like this extended to be independent of a broker implementation, and generally useful.