A curable composition comprises (a) at least one polydiorganosiloxane, fluorinated polydiorganosiloxane, or combination thereof comprising reactive silane functionality comprising at least two hydroxysilyl moieties; (b) at least one polydiorganosiloxane, fluorinated polydiorganosiloxane, or combination thereof comprising reactive silane functionality comprising at least two hydrosilyl moieties; and (c) at least one base selected from amidines, guanidines, phosphazenes, proazaphosphatranes, and combinations thereof; wherein at least one of the components (a) and (b) has an average reactive silane functionality of at least three.