The Big Switch team has been working overtime to develop a new version of the popular Indigo project. Indigo is an OpenFlow firmware agent for physical switches, and info on the current version can be found on http://indigo.openflowhub.org.
Why the need for a new version? We wanted to provided an extensible framework to enable switch and hypervisor vendors to implement OpenFlow agents, and provide an easier way to provide an upgrade path to supported new versions of OpenFlow.
Major new capabilities include a) a HAL abstraction layer to make it easy to integrate with the forwarding and port management interfaces of physical- or virtual- switches, b) a configuration abstraction layer to support running OpenFlow in a "hybrid" mode on your switch, c) LOXI - a marshalling/un-marshalling engine that generates OpenFlow libraries in multiple languages. Currently it generates C, but Java and Python are coming soon.