| Assoc | An association with 2 ends. | 
| AssocPlayer | An association  at the end of an  Assoc. | 
| AssocType | Part of DMX's type system, like a class whose instances are  Assocs. | 
| ChildTopics |  | 
| CompDef | A composition definition of a parent type and a child type -- part of DMX's type system. | 
| DMXObject | The (abstract) base class of both,  Topic and  Assoc. | 
| DMXType |  | 
| Identifiable | A common interface for all entities that provide an ID. | 
| JSONEnabled | A common interface for all entities that provide a JSON representation. | 
| Player | A  Player represents one of the 2  Assoc ends. | 
| RelatedAssoc | An Assoc-Assoc pair. | 
| RelatedObject |  | 
| RelatedTopic | A Topic-Assoc pair. | 
| RoleType | A role type is basically a topic plus a view config. | 
| Topic | A topic -- DMX's central data object. | 
| TopicPlayer | A topic  at the end of an  Assoc. | 
| TopicType | Part of DMX's type system, like a class whose instances are  Topics. | 
| ViewConfig | A container for config topics. |