Programming the Xen cloud using OCaml by David Scott, Anil Madhavapeddy and Richard Mortier.

The Xen Cloud Platform (XCP)1 is an open-source software distribution that converts clusters of physical computers into many virtual machines, all isolated from each other via the Xen hypervisor. XCP is a large, mature and widely deployed OCaml codebase that is used as mission-critical software on hundreds of thousands of hosts today.