Now at Google Project Hosting
After a few requests for the Visual Studio Solution, I've moved the source code over from my self-hosted solution to a Google Project Hosting solution. In the process, I've also Open Sourced the source code (not the chapters or the site, just the code) under the MIT license, a very permissive Open Source license that allows you to use the code for any purpose you want.
The project itself is a Visual Studio 2010 solution containing individual projects for each of the chapters. If you have Subversion, you can check out the entire project, or if you'd like to view the files in your browser, you can do so here much better than I could implement on this site. Note that even though the project is a Visual Studio solution, the source can be compiled on many platforms.