Flage: A programming language for adaptive software

We propose a programming language, Flage, for building software systems which dynamically adapt to changing local situations. In our language, we construct applications by agents; concurrent mobile objects with the metalevel architecture. Metalevel programming facilities realize a self-control of an agent's actions and an autonomous adaptation to changes. We also introduce another kind of program element called field. A field represents a local situation around agents. For example, one field represents a virtual place to get local information in a network environment and another represents a virtual place where agents do cooperative works. If an agent enters a field, it gets programs and shared information in the field. By moving field to field, an agent can change its program composition by itself and it adapts to changing local situations. In this paper, we describe the language specification of Flage, the implementation of the platform for Flage programming and show some program examples.