MvcSiteMap is a project mainly written in C# and CLASSIC ASP, it's free.
SiteMap generator for asp.net mvc
I needed a utility to automatically render Google site maps. The example is using a StackOverflow to generate data. I'll be adding examples on how to render the site map based on the current site structure, or a database.
Based on sitemaps.org schema: http://sitemaps.org/protocol.php