Big Switch Networks is a network virtualization and SDN (software-defined networking) company that was founded in 2010.
Embrane is a company that makes software products for the delivery of SDN (sofware-defined networking) services, including load balancers, firewalls and VPNs.
Nicira is a network virtualization and SDN (software-defined networking) company that Martin Casado, Nick McKeown and Scott Shenker founded in 2007.
Plexxi is a Cambridge Massachusetts company that makes software-defined networking (SDN) software. The company was founded with venture-based funding in 2011. Plexxi's management team is composed of networking professionals.