This work was supported in part by PENED project ``Exploitation of idle memory in a workstation cluster'' (2041 2270/1-2-95), in part by the USENIX Association through project ``Network RAMDISK'', and in part by the ESPRIT/OMI project ``ARCHES'' (ESPIRIT 20693), funded by the European Union. We deeply appreciate this financial support.
We also thank the Computer Science Department of the University of Rochester, and the Parallab Supercomputing Center, for giving us access to their equipment where several of the described experiments were run. Finally, we thank Manolis Katevenis and Catherine Chronaki who provided useful feedback in earlier versions of this document.