No built-in agent semantics

Swarm's original motivation was to facilitate artificial life research

Design takes a restrained approach toward the ABM paradigm.

Design aims to scale for systems in which model components are very simple and very numerous, e.g. cells in an organism.

No Agent class: Swarm does not have any feature called an "agent", does not suggest semantics for how a agent landscapes. Swarm users can and often do design objects with heavier agent semantics.