EUCALYPTUS: Elastic Utility Computing Architecture 
      for Linking Your Programs to Transiently 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 "head instance" is externally routable (as is the case
with most academic 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 Xen-enabled kernel with Xen 3.1 or later hypervisor support.  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).