AllJoyn is a collaborative open source software framework that allows devices to communicate with other devices around them. AllJoyn framework is flexible, promotes proximal network and cloud connection is optional.
The AllJoyn software framework and core system services let compatible devices and applications find each other, communicate and collaborate across the boundaries of product category, platform, brand, and connection type. Target devices include those in the fields of Connected Home, IoT, SmartCities, etc.
Alljoyn is an open source software stack for a myriad of devices, ranging from the tiniest IoT devices to the largest computers, for discovery and control of devices on networks (Wifi, Ethernet) and other links (Bluetooth, ZigBee, etc.). It uses (amongst others) mDNS and HTTP over UDP.