Thisbookgathersacollectionofrefereedarticlescontainingoriginalresultsrepo- ing the recent originalcontributions of the lectures and communications presented at the Free Boundary Problems (FBP2005) Conference that took place at the University of Coimbra, Portugal, from 7 to 12 of June 2005. They deal with the Mathematics of a broad class of models and problems involving nonlinear partial di?erentialequationsarisinginPhysics,Engineering,BiologyandFinance.Among the main topics, the talks considered free boundary problems in biomedicine, in porous media, in thermodynamic modeling, in ?uid mechanics, in image proce- ing, in ?nancial mathematics or in computations for inter-scale problems. FBP2005 was the 10th Conference of a Series started in 1981 in Monte- tini, Italy, that has had a continuous development in the following conferences in Maubuisson, France (1984), Irsee, Germany (1987), Montreal, Canada (1990), Toledo, Spain (1993), Zakopone, Poland (1995), Crete, Greece (1997), Chiba, Japan (1999), Trento, Italy (2002) and will be followed by the next one foreseen to be held in Stockholm, Sweden, in 2008. In fact, the mathematical analysis and ?ne properties of solutions and - terfaces in free boundary problems have been an active subject in the last three decades and their mathematical understanding continues to be an important - terdisciplinary tool for the scienti?c applications, on one hand, and an intrinsic aspect of the current development of several important mathematical disciplines.