Why IoT Needs a PHP (A Tour of AllJoyn)

I do not understand why things need to talk AllJoyn instead of talking CoAP or MQTT.

If AllJoyn is solving a problem that using CoAP or MQTT does not, then great, but it won't be a PHP unless it's completely opensource and I can run every part of it on my own machines.

This may be the case, though it isn't clear if this covers all the required software

https://git.allseenalliance.org/gerrit/#/admin/projects/

The AllJoyn site doesn't seem to have any obvious links for installing and running the whole thing on for yourself.