6LoWPAN vs Zigbee : The great debate between these wireless mesh technologies for IOT devices
Both Zigbee and 6LoWPAN wireless technologies are targeted at low power devices. These low power devices (read : IOT devices, if you like the buzzword) typically operate on batteries.
Fans of the Zigbee and the 6LoWPAN wireless technologies are usually passionate and unyielding in their support. All right, get your boxing gloves out and lets find out which wireless mesh technology is better!
16LoWPAN vs Zigbee wireless technology protocols: The new kid on the block fights the incumbent.

The 6LoWPAN technology is the quintessential new kid trying to dethrone the existing champion- the Zigbee protocol. The Zigbee protocol has been the standard for connecting low power devices. However, lately, a lot of folks have started seeing the advantages of the new 6LoWPAN wireless technology and have started adopting 6LoWPAN.
However, since legacy systems are already based on Zigbee technology, the Zigbee stack has more stable support from hardware vendors than 6LoWPAN.
2Communication with other protocols : 6LoWPAN beats Zigbee technology by a knockout
Zigbee devices have limited interoperability. Zigbee devices can communicate with other Zigbee devices and thats it! Zigbee definitely does not offer support for any other protocol communication
6LoWPAN devices can communicate with other 6LoWPAN devices. It can also communicate with other devices on the IEEE 802.15.4 network standard. The best part of 6LoWPAN is that it can also communicate with any IP-based protocol. For example, you can make 6LoWPAN communicate with a WiFi network with a simple network bridge.
In summary, 6LoWPAN communicates better with other protocols compared to Zigbee
3Communication with devices across the world : 6LowPan makes it easy compared to Zigbee
The IP Transport protocol implies that 6LoWPAN sensor device can easily communicate with another node anywhere in the world, as long it is on the internet
Assume a company has remote factories across the world with sensors tracking key industrial parameters. The 6LoWPAN wireless technology will make the communication between the sensor nodes easy, as long as the nodes are on the internet.
The communication between these sensor nodes can still happen with Zigbee but you will need multiple Zigbee to IP translations.
46LoWPAN : Smaller stack size in comparison to Zigbee

Firstly, lets look at the header information in the 6LoWPAN packets. Firstly, the IPV6 address data goes thru stateless compression. In addition, often, there is no information required in the header.As a result, a 6LoWPAN stack has approximately one third the code size of a Zigbee stack
56LoWPAN vs Zigbee Security : An even match
One advantage of security with the 6LoWPAN protocol is that 6LoWPAN does not need a gateway to connect to the internet, since it is IPV6 driven. Other networks such as Zigbee need a bridge or a gateway to connect to the internet and this builds in another layer of vulnerability
6LoWPAN also offers a secure and non-secure mode but the overall security in 6LoWPAN is a work in progress. In comparison, Zigbee has a more robust and tested security protocol
6The 6LoWPAN vs Zigbee wireless technology war: Equal support by IC hardware vendors

TI, Atmel, Freescale and other IC hardware vendors support both Zigbee and 6LoWPAN technologies. The top Zigbee modules and 6LoWPAN development kits are created by the top manufacturers.