notation. See also Z User Group (ZUG) Community Z Tools (CZT) project Other formal methods (and languages using formal specifications): VDM-SL, the main alternative to Z B-Method, developed by Jean-Raymond Abrial (creator of Z notation) Z++ and Object-Z : object extensions for the Z notation Alloy, a specification language inspired by Z notation and implementing the principles of Object Constraint Language (OCL). Verus, a proprietary tool built by Compion, Champaign, Illinois (later purchased by Motorola), for use in the multi-level secure UNIX project pioneered by its Addamax division. Fastest is a model-based testing tool for the Z notation. References Further reading Computer-related introductions in 1977 Specification languages Formal specification languages Oxford University Computing Laboratory