A group of enzymes that catalyze the hydrolysis of diphosphate bonds in compounds such as nucleoside di- and tri-phosphates, and sulfonyl-containing anhydrides such as adenylylsulfate. (Enzyme Nomenclature, 1992) EC 3.6.

Synonyms: Hydrolases, Acid Anhydride, Acid Anhydride Hydrolases, Anhydride Hydrolases, Acid, EC 3.6.-