From (Abelson et al. 2000):
A colony of cells cooperates to form a multicellular organism under the direction of a genetic program shared by the members of the colony. A swarm of bees cooperates to construct a hive. Humans group together to build towns, cities, and nations.
Amorphous computing was coined by Abelson, Knight, Sussman et al. It refers to computational systems composed of a large number of identical parallel devices (processors) with limited computational capacity. The processors interact locally, without particular knowledge of their position in the medium.
[…] this paper argues that now is an opportune time to tackle the engineering of emergent order: to identify the engineering principles and languages that can be used to observe, control, organize, and exploit the behavior of programmable multitudes.
Cellular automata can be seen as a kind of elementary amorphous computing device.