Preliminaries.- L-projections and M-projections.- M-Ideals.- The centralizer.- Function modules.- M-Structure of some classes of Banach spaces.- Remarks.- The Banach-Stone theorem.- The Banach-Stone property and the strong Banach-Stone property.- Centralizer-norming systems.- M-structure of Co(M,X).- Generalizations of the Banach-Stone theorem.- Remarks.