We contend that the complexity of modern computer systems is caused by a dependency on a plethora of mechanisms that by their lack of coherence increase the cost of developing applications. By integrating these mechanisms we can reduce the complexity of the system and thereby achieve savings throughout product life cycles. From our experience in operating systems, programming languages and databases we identify five major areas of system design for modern systems: controlling complexity, orthogonal persistence, controlled system evolution, protection of data and concurrent computation. We are currently engaged in building a system which will achieve the simplicity above and here we describe the design issues involved in the construction of a persistent information space architecture (PISA) capable of integrating all these activities. 1.