The IIS SEO Toolkit includes a lot of functionality built-in such as built-in violation rules, processing of different content types (like HTML, CSS, RSS, etc) and more, however it might not do all the things that you would need it to do, for example, it might not process a set of documents that you use, or it might not gather all the information that you are interested in while processing a document. The good news is that it includes enough extensibility to let you build on top of its rich capabilities and provide additional ones easily using .NET.

There are three main extensibility points in this first release, including:

1. Crawler Module. This extensibility point allows you to provide your own code to hook to the process of crawling a Web site in the Site Analysis process. Using this extensibility point you can extend the built in set of violation rules with your own. You can also gather additional information such as links or any metadata of a resource, whether directly extracted from the content or from an external system.
2. Site Analyzer Extension. This feature allows you to provide your own set of tasks to be exposed in the Site Analysis user interface. These tasks will be displayed in the main menu bar in the report dashboard.
3. Sitemap Extension. This class allows you to provide your own set of tasks to be exposed in the Sitemaps, Sitemap and Sitemap Index user interface.

This is the first of a series of extensibility blog entries for the IIS SEO Toolkit where I will cover all of the extensibility points mentioned above.