Odysseas Pentakalos has been an independent consultant for 10 years, dealing with performance modeling and tuning of computer systems, as well as object-oriented design and development. His clients have included major government agencies and corporations such as NASA, the Army Research Lab, Sun Microsystems, and Concert Communications. Odysseas received a Ph.D. in computer science from the University of Maryland. He has published papers on performance topics in conferences, journals, and commercial publications.