(.. This section of documentation is just a start.)
The defobj library currently includes the Object_s and CreateDrop superclasses used by other libraries. For user objects in Swarm simulations the SwarmObject superclass in the swarmobject library packages all required behavior of these superclasses in a single, simpler superclass.
Subclassing from classes that implement object types (see module definition conventions for a summary of the differences between types and classes) is still complex. In general, classes that implement a library are not automatically available for user as superclasses. A library must document specifically which superclasses are published for user classes to inherit from, along with specific rules that user subclasses must follow when implementing new behavior.
In the case of the defobj library, the only currently published superclasses are the ones which are repackaged by the SwarmObject superclass of the swarmobject library. (.. More subclassing information to be provided, but just use SwarmObject for now.)