Introduction

This paper presents ideas for building MASs. The ideas have a biological inspiration. This work should be contrasted with the economic techniques such as auctions and bargaining.
As software engineering has progressed, more and more control has become localized. Before, the decision of what exactly a piece of code should do was mostly determined by outside influences (e.g., the programmer, parameters, function calls).

Increasing Software Localization
	Monolithic Program	Structured Programming	Object-Oriented Programming	Agent-Oriented Programming
How does a unit behave?	External	Local	Local	Local
What does a unit do when it runs?	External	External	Local	Local
When does a unit run?	External	External (called)	External (message)	Local

Agents localize code, data, and invocation.
The number of system behaviors possible is an exponential of the number of individual agent behaviors. The problem, however, is how to engineering the simple agent behaviors so that they achieve the required system behavior.