OpenStack Folsom is the follow-up to the Essex release of the OpenStack open source cloud computing platform. OpenStack Folsom debuted in September 2012, seven months after the OpenStack Essex release, and represents the efforts of more than 330 contributors who worked on adding 185 different features.
Among OpenStack Folsom’s most notable new enhancements are a Software-Defined Network (SDN) project called Quantum and Block Storage services known as Cinder. The Folsom release additionally adds Hyper-V support, a new translation framework and various other cloud enhancements.
The Ubuntu 12.10 release (“Precise Pangolin”) is the first major Linux-based operating system to support Folsom as part of a production-grade release. Work on the successor to OpenStack Folsom, codenamed “Grizzly,” is already under way as well.
See also "A Cloud Computing Dictionary Resource" in Webopedia's Quick Reference section.