A WPF based selector control in the shape of the Periodic Table of Elements that's written in C#.
Currently the only to get it, is to run the Visual Studio solution on your computer and compile it. A demo application is included with the solution.
This code is Licensed under the Microsoft Reciprocal License (Ms-RL). Why, because it lets you use the code in a commerical application without forcing you to use the same license for the code that uses it.