A programming model for active documents

Abstract

Traditionally, designers organize software system as active end-points (e.g. applications) linked by passive infrastructures (e.g. networks). Increasingly, however, networks and infrastructures are becoming active components that contribute directly to application behavior. Amongst the various problems that this presents is the question of how such active infrastructures should be programmed. We have been developing an active document management system called Placeless Documents. Its programming model is organized in terms of properties that actively contribute to the functionality and behavior of the documents to which they are attached. This paper discusses active properties and their use as a programming model for active infrastructures. We have found that active properties enable the creation of persistent, autonomous active entities in document systems, independent of specific repositories and applications, but present challenges for managing problems of composition.