He held visiting professor positions at Boston University and Polytechnic University of Catalunya, in Barcelona visiting appointments at Xerox PARC and Hewlett-Packard Research Laboratory. His research interests include performance models and tools of complex systems to analyze large scale distributed systems. Virgilio is a recipient of a Fulbright Research Scholar Award and a full member of the Brazilian Academy of Sciences. He is also member of the Advisory Board of the Brazilian Council for Scientific and Technological Development -CNPq for 2010/2011. Virgilio is an International Fellow of the Santa Fe Institute for 2008/2009. He is a member of the Editorial Board of Internet Computing, First Monday and Journal of Internet Services and Applications.