Internet Information Services (IIS) is a set of Internet-based services for servers using Microsoft Windows. It is the world's second most popular web server in terms of overall websites.

IIS can be used to run Nectil in conjunction with the PHP Isapi Filter (by default IIS only serves ASP.NET).

IIS 6.0 is provided with Windows Server 2003 and Windows XP Professional x64 Edition, IIS 7.0 with Windows Vista and Windows Server 2008.