Wolverine Software Corporation was founded in 1976 by James O. Henriksen. Wolverine's first product, GPSS/H for IBM mainframes, was introduced in 1977.In 1989, Wolverine introduced Proof Animation, a new, state-of-the-art, general purpose animation package. Proof 3D was introduced in 2008.Wolverine's newest simulation product, SLX, is a general-purpose simulation language designed for modelers who need flexibility and extensibility, plus the traditional Wolverine emphasis on blazing speed, even when running large, complex models. SLX offers a layered approach to simulation modeling. A modeler can choose different levels of programming detail, ranging from a powerful kernel layer that lets one build a custom simulation language to upper layers consisting of user-friendly "simulators". SLX's kernel provides powerful building blocks, and its extensibility mechanisms make it easy to move up to higher levels of abstraction.