ZigBee dominates the low-power networking market, and WiFi and Bluetooth are trying to enter this market with low-power WiFi and Bluetooth Low Energy (BLE) respectively.
The Bluetooth Special Interest Group (SIG) has announced an initiative to make Bluetooth ?networking-capable? by enabling its networking layer to not only connect a set of wearables around a single device, but to extend the connectivity to a larger set of independent devices working together in a Mesh Network.