Libgee is a collection library providing GObject-based interfaces and 

classes for commonly used data structures.

Libgee provides the following interfaces:

     * Traversable

           o Iterable

                 + Collection

                       # List

                             * BidirList

                       # Set

                             * SortedSet

                                 o BidirSortedSet

                       # MultiSet

                       # Queue

                             * Deque

                 + Map

                       # SortedMap

                             * BidirSortedMap

           o Iterator

                 + BidirIterator

                       # BidirListIterator

                 + ListIterator

                       # BidirListIterator

     * MultiMap

     * Future

The ArrayList, ArrauQueue, ConcurrentLinkedList, ConcurrentSet, HashSet,

HashMap, HashMultiSet, HashMultiMap, LinkedList, PriorityQueue, TreeSet,

TreeMap, TreeMultiSet, and TreeMultiMap classes provide a reasonable sample

implementation of those interfaces. In addition, a set of abstract

classes are provided to ease the implementation of new collections.

Around that, the API provide means to retrieve read-only views, 

efficient sort algorithms, simple, bi-directional or index-based mutable 

iterators depending on the collection type.

Libgee is written in Vala and can be used like any GObject-based C 

library. It's planned to provide bindings for further languages.