The Free On-line Dictionary of Computing (30 December 2018):
GVL Graphical View Language. A visual language for specifying interactive graphical output by T.C.N. Graham & J.R. Cordy, Queen's University, Canada. ["GVL: A Graphical, Functional Language for the Specification of Output in Programming Languages", J.R. Cordy & T.C.N. Graham, Proc IEEE Intl Conf on Comp Lang ICCL'90 (March 1990)].