The project is out on GitHub and even has a NuGet package so it can be easily used by web developers. Full documentation is currently in the README file on the GitHub page.
In the process of preparing FluentSiteMap for the OSS world, I also published two more projects, both used by FluentSiteMap:
- NUnitExtensions - Handy base test classes and other extensions useful for TDD using NUnit (also has a NuGet package)
- Buildage - The easy build and packager for C# projects (integrates into other projects using Git submodules)
So feel free to check it out and contribute to the projects if you like! Since the original code is slightly dated, FluentSiteMap is actually based on ASP.NET MVC2, so right out of the box it could use an upgrade to the newer versions of MVC (although I think it works fine in MVC3/4). Version 1.0.0 also shipped with a bug (imagine that!) that I felt was low enough priority not to delay the initial OSS release. You can see the list of current issues here.