ISAPI_Rewrite is a powerful regular-expressions-based URL rewriter for IIS. It is compatible with Apache mod_rewrite making it possible to move configurations from Apache to IIS and vice versa just by copying .htaccess files. It is used for search engine optimization, to proxy another server's content, stop hotlinking or strengthen server security.

Top features of ISAPI_Rewrite:
The same syntax and behavior as of Apache mod_rewrite make it possible to migrate configurations just by copying .htaccess files. Read more about mod_rewrite compatibility here.
Regular expressions for flexible and powerful configurations.
Extremely fast and highly scalable pure C++ code.
Real distributed configurations: global server level, virtual host (web site) level, directory level .htaccess files with real-time monitoring.
Isolation - user level configuration affects only local user environment making ISAPI_Rewrite an ideal solution for web hosting providers.
Top usage examples:
1. Search engine optimization.
2. Proxying content of one web server through another web server.
3. Prevention of content leeching (direct linking).
4. Blocking specific hosts, referrers or annoying robots.
5. Content negotiation - serving different files for different language or different browsers.
6. Load balancing emulation for web cluster.

The license of this software is Free Trial Software, the price is $99, you can free download and get a free trial.