Professor Maxime Crochemore received his PhD in 1978 and his Doctorat d'état in 1983 at the University of Rouen. He got his first professorship position at the University of Paris-Nord in 1975 where he acted as President of the Department of Mathematics and Computer Science for two years. He became professor at the University Paris 7 in 1989 and was involved in the creation of the University of Marne-la-Vallée where he is presently Professor. He also created the Computer Science research laboratory of this university in 1991, which has now more than fifty permanent researchers. He was the director of the laboratory until 2005. Professor Crochemore is Senior Research Fellow at King's College London since 2002. Christophe Hancart received his PhD in Computer Science from the University of Paris 7, France. He is now an assistant professor in the Department of Computer Science at the University of Rouen. Thierry Lecroq received his PhD in Computer Science from the University of Orléans in 1992. He is now a professor in the Department of Computer Science at the University of Rouen.