Peter Sestoft released version 1.0 of his C5 generics library for C#, it is available here:
C5 provides functionality and data structures not provided by the standard .Net System.Collections.Generic namespace, such as tree data structures, heap based priority queues and hash indexed array lists and linked lists, making it more comprehensive than collection class libraries on similar platforms, such as Java. Unlike many other collection class libraries, C5 is designed with a strict policy of supporting "code to interface not implementation".
Mono bundles his old 0.5 library, we will be upgrading the library soon.
Posted on 01 Feb 2006