EUCALYPTUS: Elastic Utility Computing Architecture 
            for Linking Your Programs To Useful Systems

EUCALYPTUS is an open source service overlay that implements elastic
computing using existing resources. The goal of EUCALYPTUS is to allow
sites with existing clusters and server infrastructure to co-host an
elastic computing service that is interface-compatible with Amazon's
EC2.

Because EUCALYPTUS is designed to function as an overlay, it must be
able to incorporate resources from different clusters or pools.  For
example, EUCALYPTUS allows its administrator to set up a "cloud" that
permit users to virtualized OS instances on a number of clusters
transparently.  Enabling the necessary network interconnectivity in a
way that is secure and portable is one novel feature of EUCALYPTUS.
Another stems from its ability to provide interface compatibility with
the existing Amazon EC2 service.  EUCALYPTUS users can develop using
their own local resources and then transition directly some or all of
their functionality to EC2.

Finally, a key requirement of EUCALYPTUS is that it be able to serve
as a research platform for elastic computing.  To this end, its design
makes two significant contributions.  The first concerns the use of
scarce network resources in a structured way.  A EUCALYPTUS allocation
can function equally well in an environment in which all processors
have externally routable IP addresses (e.g. Amazon's current
environment) as well as one in which only a certain "front-end
machine" is externally routable (as is the case with many production
and research clusters today).  Secondly, EUCALYPTUS leverages the
extensive Linux packaging and deployment support that is currently
available while requiring minimal modification to the existing
installed OS base.  Specifically, the target resources need only run a
standard hypervisor (Xen, KVM), along with common open-source Linux
utilities.  All other functionality installs directly without need for
kernel patching or module additions to the host OS domain.

For more information and complete documentation, please visit our
website (http://open.eucalyptus.com).