IIS Mod-Rewrite download comes as "try before you buy" product. It will work in full function for unlimited time for all http requests originating from localhost, or for a limited time (30 minutes, or 1000 requests, whichever is reached first) for all non-localhost http requests until your webserver is restarted. To enable IIS Mod-Rewrite to work without time or usage limitations, you need to purchase a license key and activate the product.

IIS Mod-Rewrite Pro v3.5

Supports per-server, per-virtual host, per-directory and override (.htaccess) configurations. It implements all Apache mod_rewrite features. Works with IIS 6.0 and 7.0*.

IIS Mod-Rewrite Standard v3.5

Supports per-server and per-virtual host configurations. It implements most of Apache mod_rewrite features. Works with IIS 5.0, 5.1, 6.0 and 7.0*.

*IIS 7.0 must have full IIS 6.0 compatibility features enabled