ISAPI_Rewrite is a powerful URL manipulation engine based on regular expressions. It acts mostly like Apache's mod_Rewrite, but is designed specifically for Microsoft's Internet Information Server (IIS). ISAPI_Rewrite is an ISAPI filter written in pure C/C++ so it is extremely fast. ISAPI_Rewrite gives you the freedom to go beyond the standard URL schemes and develop your own scheme. It can be used to hide the internal structure of your web site, to correct mistyped URLs, and/or strengthen server security. You can even implement host-header-based hosting using the ISAPI_Rewrite only. And you can find a variety of useful examples in the ISAPI_Rewrite product documentation.