libgee is a collection library providing GObject-based interfaces and classes
for commonly used data structures.

libgee provides the following interfaces:

    * Iterable
          o Collection
                + List
                + Set
    * Iterator
    * Map

The ArrayList, HashSet, and HashMap classes provide a reasonable sample
implementation of the List, Set, and Map interfaces. ReadOnlyCollection,
ReadOnlyList, ReadOnlySet, and ReadOnlyMap are read-only wrapper classes that
prevent modification of the underlying collection.

libgee is written in Vala and can be used like any GObject-based C library.
It's planned to provide bindings for further languages.