NeXt is an ODL web interface for visualizing a network and the communication within this network. It's an open graphical tool that can show physical or virtual network elements, such as traffic, tunnel path, and groups and their attributes. Also, it can build a layered topology, for example, to show the overlay network over the underlay. It can work together with Dlux to build ODL apps.
NeXt is highly contributed by Cisco and you can find many enhancements of NeXt in Cisco DevNet.
The following image illustrates NeXt:
