Swarm objects are Objective C objects
Non-Swarm objects can be used -- `pure Java'
Swarm objects can be extended in Java
Objective C extension: customized types
Object customization lets one take a class, change some default values, and get a new class that when instantiated will include those changes. This is important because some of the Swarm interfaces have methods that take classes as arguments.
For example, a tardiness policy could be thought-of as the set of methods associated with a type. Using the same basic policy, a teacher's method "showedUpLateForClass (student)" throw the kid in detention when the principal configured handed the teacher(s) a policy customized with "crackdownFlag".