Modular programming is a language independent key factor in reducing the complexity of software development. It allows programmers to split a programming task into smaller, independent programming tasks. In this thesis we show how to construct interactive programs in a modular fassion based on interactive processes. The concept of interactive process is more general than the concept of interactive program. An interactive process is in essence a state transition system, and is specified in exactly the same way as interactive programs earlier.
Interactive programs consist of an arbitrary number of interactive processes.
O. It is shown that interactive processes can be evaluated purely sequentially, in an interleaved fassion, but also in parallel. Both forms of communication integrate smoothly in the system. Data sharing is a form of communication by a common piece of global data. Access to this data is restricted to one process at a time. Provided that interactive processes have the identification of a given interactive process they can send messages to that interactive process.