ISAPI_Rewrite is Apache .htaccess mod_rewrite compatible URL rewriter for Microsoft IIS. It is used for search engine optimization, to reverse proxy another server's content, stoping hotlinking and strengthening server security.
This software is not reviewed yet.
LinkFreeze is a powerful tool to optimize dynamic or database-driven websites for search engines. Conveniently, you don't need to rewrite the code of your pages, as all your links are modified on-the-fly whenever a page is requested on the server.