From 3 February to 8 February 2008, the Dagstuhl Seminar 08061 State" Conference and Research Center (IBFI), Schloss Dagstuhl. 45 researchers, with interests and expertise in many different aspects of modelling and reasoning about mutable state, met to present their current work and discuss ongoing projects and open problems. Keywords. Mutable State, Program Logics, Semantics, Type Systems, Program Analysis