Vasy is an Inria project team that is also a team of the Lig laboratory, a joint research unit of Centre National de Recherche Scientifique, Grenoble Inp , Université Joseph Fourier, and Université Pierre Mendès-France. This is the last yearly activity report for Vasy , as it completed its scientific activities on December 31, 2011 after having reached the 12-year age limit for Inria project teams. As of January 2012, the Vasy team members have launched a new research team named Convecs (see http://convecs.inria.fr ).