Process algebras can be enriched with localities that explicitly describe the distribution of
processes. Localities may represent physical machines, or more generally distribution units
where processes are grouped according to some criterion like the sharing of resources. In a
concurrent process, localities are naturally associated with (groups of) parallel components.
These localities then intervene in the semantics of processes and become part, to some
extent, of their observable behaviour. In a first line of research, initiated in the early nineties …