ThisvolumecontainstheproceedingsofMPC2008, the9thInternationalConf- enceontheMathematicsofProgramConstruction.Thisseriesofconferencesaims to promote the development of mathematical principles and techniques that are demonstrably useful in the process of constructing computer programs, whether implemented in hardware or software. The focus is on techniques that combine precision with conciseness, enabling programs to be constructed by formal c- culation.Within this theme, the scopeofthe seriesisverydiverse, including p- grammingmethodology, programspeci?cationandtransformation, programming...