The URL Rewrite module is fully supported by Microsoft according to the Windows Supplemental license; it works on IIS 7 and will be incorporated into future versions and targets some key url rewriting scenarios. Although there are a lot of compelling reasons to use this module, you should evaluate your requirements to determine the best solution. For example, if you need URL rewrite functionality for past versions of IIS, or if you need syntax compatibility with mod_rewrite rules within .htaccess files, then ISAPI_Rewrite may be a good option to consider.