| ActionReferenceQueue | The extended reference queue allows for adding (weak) 
  object with an associated action. | 
| ArrayBlockingQueue<T> | Blocking queue implemented as array. | 
| BiHashMap<K,V> | A bidirectional hash map. | 
| BlockingQueue<T> | A blocking queue allows to enqueue or dequeue
  elements. | 
| BloomFilter | A bloom filter is a probabilistic data structure for
  checking if a value is contained in a set. | 
| Cache | Cache that provide expiration in case of
  a) timetolive is exceeded
  b) the max number of data has been reached (lru behaviour) | 
| CacheEntry | Entry for cache. | 
| CheckedCollection | A checked collection can be used for concurrent modification bug tracking. | 
| CheckedMap |  | 
| ConcurrencyCheckingList | A wrapper for a list to detect undesired
  concurrent access. | 
| FastHashMap | Implements a map from strings to objects as a hash table. | 
| IdentityHashSet<T> | A set based on identity comparison. | 
| IndexMap<K,V> | This class combines the list and map interface. | 
| IndexMap.ListIndexMap<K,V> | Provide access to the index map via list interface. | 
| IndexMap.MapIndexMap<K,V> | Provide access to the index map via map interface. | 
| LeaseTimeMap<K,V> | Lease time map with supervised write/update access. | 
| LeaseTimeSet<E> | Collection that remove elements after a lease time automatically. | 
| LeaseTimeSet.SynchronizedLeaseTimeCollection<E> | Synchronized lease time collection. | 
| LRU<K,V> | A least recently used map. | 
| MapEntry<K,V> | Replacement for Map.Entry which cannot be instantiated :-( | 
| MultiCollection<K,V> | An MultiCollection is a map with the ability
  to store more than one element per key (an collection). | 
| MultiIterator<T> | Iterator that operates over multiple collections. | 
| NestedMap | A nested map refers to parent maps for entries
  not found in this map. | 
| OrderedProperties | Class extending java.util.Properties to preserve order
  by redirecting calls to an internal linked hash map. | 
| PassiveLeaseTimeSet<E> | Collection that remove elements after a lease time on trigger. | 
| RwAutoLock | Class wrapping a read-write lock mechanism that can be used
  with try-with-resources. | 
| RwMapWrapper<K,V> | Thread-safe wrapper for maps that uses a read/write lock. | 
| SCollection | Static methods for collection creation and observation. | 
| SCollection.DebugPrinter | Create an info printer for the collections. | 
| SortedList<T> | A sorted list allowing duplicates of elements
  (unlike java.util.TreeSet). | 
| TimerDelayRunner | Timer based on Java java timer. | 
| Tree | Tree data structure. | 
| TreeNode | Represents a node of a tree. | 
| TwoWayMultiCollection | The two-way multi-collection allows fast reverse lookup,
  by containing a second multi-collection,
  which reversely maps values to keys. | 
| WeakEntry<T> | A weak entry is a reference with an additional argument
  that can be inspected the referent is garbage collected. | 
| WeakKeyValueMap<K,V> | HashMap with weak reference on both sides. | 
| WeakList<E> | A list with weak entries. | 
| WeakObject<T> | Weakreference has the disadvantage that it does not support
  transparent equals() and hashcode() methods. | 
| WeakSet<T> | A weak set for entries that will be automatically removed when
  no references to them are existing any more. | 
| WeakValueMap<K,V> | A map with weak values. |