Hypermedia and object oriented programming systems (OOPs) represent examples of "open" computer environments that allow the user access to parts of the code or operating system. Both systems share fundamental intellectual concepts (objects, messages, methods, classes, and inheritance), so that an understanding of hypermedia can help in the understanding of OOPs and vice versa. The degree to which the concepts are intellectually and operationally parallel, however, differs markedly for particular hypermedia applications. Other comparisons reveal that both systems are designed to emulate the way humans store and retrieve data, and both allow a non-linear method of searching for information. Hypermedia and OOPs appear to be the likely tools for the development of interactive user interfaces to other developed programs. They are both systems that force the programmer to look at knowledge from the learner's perspective and needs. (DB)