LeechBlocker is an open source ISAPI Filter for Microsoft`s Internet Information Services by Michael R. Brumm. This Isapi filter can be very easily added to any IIS web site, and can protect the whole server or just a single site from leeching.  

Many web sites suffer from others directly linking to their image, video and other content. This practice is called often called leeching, hot-linking, or inline-linking and causes wasted bandwidth and increased server load to the victim web site. Mike Volodarsky wrote a ASP.NET module that prevents hot linking. It can be used on IIS5 (Windows 2000/XP), IIS6 (Windows Server 2003), and IIS7 (Windows Vista / Longhorn Server).

Windows 2000 and XP (Professional) are only able to run one website at a time, when you are developing in a multisite environment it is practically impossible particularly when one site depends on another. Using Multisite one can extend IIS to run as many websites as you need. The Multisite filter is an ISAPI filter which runs at the root, interrogates the host header of the incoming http request and on the outcome of that redirects the request to the relevant place in the filesystem.

IISxpress is a compression plugin for the IIS web server found on Microsoft Windows 2003, Vista, Windows XP Professsional and Windows 2000. IISxpress couples the industry standard ZLIB compression library with a powerful rules engine to offer the best compression solution available for IIS.

Microsoft is excited to announce the release of FastCGI for IIS, a new component for Microsoft's Web server platform. This release is available immediately for IIS 6.0 in Windows Server 2003.