At CloudOpen in New Orleans, KVM veterans Avi Kivity and Dor Laor revealed their latest venture, a new open-source (BSD license) operating system named OSv. OSv can run existing Linux programs and runtime environments such as a JVM, but unlike Linux, OSv was designed from the ground up to run efficiently on virtual machines. For example, OSv avoids the traditional (but slow) userspace-kernel isolation, as on the cloud VMs normally run a single application. OSv is also much smaller than Linux, and breaks away from tradition by being written in C++11 (the language choice is explained in in this post).

http://linux.slashdot.org/story/13/0...x-in-the-cloud