Preview release of Wintellect's PowerCollections for .NET

Good news in my inbox from the folks at Wintellect:

This month, Wintellect announces the availability of a preview release of its new open source collection class library for .NET 2.0 called Power Collections .NET.
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Wintellect and Microsoft are co-sponsoring the development effort but ultimately the code will belong to the development community. We urge developers to input their ideas, suggestions and review the classes as they are made available.
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Of course, the big advantage of .NET 2.0 collections is that they will be type safe and avoid boxing via the use of generics. We’re not going to re-implement collections provided in the Base Class Library (known as the BCL). Anything beyond the BCL that will be readily required (or that the community can make a good argument for), we are going to implement in Power Collections. A starting set will be ordered and unordered Set, Bag, Dictionary (unique and duplicate keyed versions), Double-ended Queue, and Priority Queue. We’ll be adding some utility types, like Pair and Triple and some built-in algorithms. You can review the current version of the specification at https://www.wintellect.com/powercollections/spec.aspx

You can find out more about PowerCollections at Peter Golde's blog.

Update: Brad Abrams points to Peter Sestoft's C5 project, which “is much more complete and is a parallel library to System.Collections.Generic rather than … a natural extension of the BCL library”. Choices are good!