Name: Apache Hadoop, hadoop.apache.org
Major Contributors: Apache Software Foundation, Yahoo, Google, Microsoft, Cloudera
Purpose: Has developed an open-source version of Google's MapReduce and File System infrastructure for processing large amounts of data in parallel, a necessity in cloud computing.

Name: Eucalyptus, www.eucalyptus.com
Major Contributors: Building on an NSF-funded project at the University of California, Santa Barbara, Eucalyptus Systems launched in April with funding from Benchmark Capital and BV Capital
Purpose: Is commercializing an open-source platform for building private clouds using existing hardware and software, which can then be merged with a public cloud like Amazon Web Services. This hybrid approach allows companies to move data and applications in and out of the public cloud as the need arises

Name: Open Cirrus, www.opencirrus.org
Major Contributors: HP, Intel, Yahoo, University of Illinois at Urbana-Champaign, Karlsruhe Institute of Technology (Germany), Infocomm Development Authority (Singapore)
Purpose: A test bed for researchers studying how to design and manage data centers for the cloud.

Name: Google/IBM Cloud Computing University Initiative
Major Contributors: University of Washington; Carnegie Mellon; MIT; Stanford University; University of California, Berkeley; University of Maryland
Purpose: Gives academic researchers and students access to the sponsors' huge computing resources so they may experiment with the design and management of cloud applications and services.

Name: Reservoir www.reservoir-fp7.eu
Major Contributors: IBM, SAP, Sun Microsystems, Telefonica, University of Messina, University College of London, Umea University, Universidad Complutense de Madrid, University of Lugano, Thales Group, Elsag Datamat, CETIC
Purpose: An EU-funded project that promotes research into creating a service-based online economy based on distributed computing in an open cloud.