This module provides a framework for generating UUIDs (Universally
Unique Identifiers, also known as GUIDs (Globally Unique Identifiers).
A UUID is 128 bits long, and is guaranteed to be different from all
other UUIDs/GUIDs generated until 3400 A.D.  Currently many different
technologies rely on UUIDs to provide unique identity for various
software components.

The algorithm for UUID generation, used by this extension, is described
in the Internet Draft "UUIDs and GUIDs" by Paul J. Leach and Rich Salz.
It provides reasonably efficient and reliable framework for generating
UUIDs and supports fairly high allocation rates - 10 million per second
per machine, and therefore, is suitable for identifying both - extremely
short-lived and very persistent objects on a given system as well as
across the network.

See also: http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt