Interoperability is a qualitative property of computing infrastructures that denotes the ability of the sending and receiving systems to exchange and properly interpret information objects across system boundaries. Since this property is not given by default, the interoperability problem involves the representation of meaning and has been an active research topic for approximately four decades. Early database models such as the Relational Model used schemas to express semantics and implicitly aimed at achieving interoperability by providing programming independence of data storage and access. After a number of intermediate steps such as Object Oriented Data Bases and Semi – Structured Data such as hypertext and XML document models, the notions of semantics and interoperability became what they have been over the last ten years in the context of the World Wide Web and more recently the concept of Open Linked Data. The talk will concentrate on the early history but also investigate the (reoccurring) problem of interoperability as it can be found in the massive data collections around the Open Linked Data concepts. We investigate semantics and interoperability research from the point of view of information systems. It should give an overview of existing old and new interoperability techniques and point out future research directions, especially for concepts found in Open Linked Data and the Semantic WEB.