1. Anderson, D.P.: Opinion - Volunteer computing: Grid or not Grid? iSGTW newsletter (July 4, 2007)
2. gLite, http://glite.web.cern.ch/glite/
3. Advanced Resource Connector (ARC), http://www.nordugrid.org/middleware/
4. Globus, http://www.globus.org/
5. Unicore, http://www.unicore.eu/