With this edition, "NGINX Plus [Release 3] builds a complementary application delivery solution on top of the NGINX open-source software technology, focusing on web application acceleration, content and application delivery, Layer 7 load balancing and request routing. Users benefit from reduced complexity of operations, additional features, certified builds and expert support."
Specifically, NGINX Plus, the new features allow you to:
Shape and control traffic to application servers for improved performance and reliability, particularly under unexpectedly-high traffic spikes;
Support dynamic DNS-based load balancing configuration;
Enable highly-available SPDY and WebSockets load balancing in conjunction with Amazon ELB, through support of the novel PROXY protocol