The Machine and Tool Ontology (MATO) represents a semantic model for the general description of equipment used in the development of production technologies. The equipment is described by properties like manufacturer, model, physical location, and a specific application area, as well as by using freely formulated expressions in natural language. MATO enables the expression of possible combinations of different equipment types required to fulfill a specific action. Furthermore, MATO semantically relates equipment with agents such as persons and organizations responsible for them.