Valter Roesler is an associate professor at the Federal University of Rio Grande do Sul (UFRGS), Brazil. He has a PhD degree (2003) and Master degree (1993) in Computer Science, and BSc in Electrical Engineering (1988). He coordinates the PRAV laboratory (Projects in Audio and Video) since 1998, and his interest areas are Multimedia, Computer Networks and eHealth.Eduardo Barrere is a professor at the Federal University of Juiz de Fora (UFJF), Brazil. He has Ph.D. degree (1996) and Master degree in Systems Engineering and Computing (UFRJ). He coordinates the LapIC laboratory (Applications and Innovation in Computing), developing research in development and use multimedia applications and information retrieval in video.Roberto Willrich received the B.S. and M.Sc. degrees in electrical engineering from the Federal University of Santa Catarina (UFSC), Florianopolis, Brazil, in 1988 and 1991, respectively, and the Ph.D. degree from Université Paul Sabatier, Toulouse, France, in 1996. Also, he was a visiting researcher at LAAS-CNRS in 2005-2006. He is currently a full professor of Computer Science with the UFSC. His research interests include recommender systems, knowledge systems, semantic Web, and annotation systems.