When developing applications using OpenFlow, a small network of OpenFlow switches is often needed for testing and debugging. Using an emulated OpenFlow network for such development would be ideal, allowing more people to develop efficiently at their own pace. Mininet is developed to serve this demand. You can create virtual OpenFlow networks in your very own desktop/laptop.
OpenFlow is an open standard that enables researchers to run experimental protocols in the campus networks we use every day. OpenFlow is added as a feature to commercial Ethernet switches, routers and wireless access points – and provides a standardized hook to allow researchers to run experiments, without requiring vendors to expose the internal workings of their network devices. OpenFlow is currently being implemented by major vendors, with OpenFlow-enabled switches now commercially available.
See a video about how OpenFlow is changing Networking.