| BreadthConceptHierarchyIterator | Iterates hierarchy of concepts, breadth-first. | 
| DepthFirstConceptIterator | Traverse hierarchy of  SConcepts for a given concept (inclusive), visiting super-concepts first
 then super-interfaces in an order they were specified in super-concepts (breadth-like). | 
| DescendantsTreeIterator | Iterator for a  SNode sub-tree. | 
| FilterIterator<T> | Iterator that uses  Condition to filter out undesired elements. | 
| ImmediateParentConceptIterator | Concept hierarchy iterator that walks direct super concepts only, up to specified concept (exclusive)
 or a top-most concept (BaseConcept, inclusive). | 
| InstanceOfCondition | SNode condition which is satisfied with an instance of specified concept. | 
| TreeFilterIterator<T> | Iterator that uses condition to filter out complete sub-tree. | 
| UniqueIterator<T> | Ensures elements coming from iterator are unique. |