The IIS Search Engine Optimization (SEO) Toolkit helps Web developers, hosting providers, and Web server administrators to improve their Web site’s relevance in search results by recommending how to make the site content more search engine-friendly. The IIS SEO Toolkit includes the Site Analysis module, the Robots Exclusion module, and the Sitemaps and Site Indexes module, which let you perform detailed analysis and offer recommendations and editing tools for managing your Robots and Sitemaps files.

More can found here http://www.iis.net/extensions/SEOToolkit