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.

What you can do with ISAPI_Rewrite:

• Optimize your dynamic content like forums or e-stores to be indexed by a popular search engines.
• Block hot linking of your data files by other sites.
• Develop a custom authorization scheme and manage access to the static files using custom scripts and database.
• Proxy content of one site into directory on another site.
• Make your Intranet servers to be accessible from the Internet by using only one Internet server with a very flexible permissions and security options.
• Create dynamic host-header based sites using a single physical site.
• Create virtual directory structure of the site hiding physical files and extensions. This also helps moving from one technology to another.
• Return a browser-dependent content even for static files.

And many other problems could be solved with the power of the regular expression engine built into the ISAPI_Rewrite.