IIS (Microsoft Internet Information Services or Server) is a set of Internet based services for Windows machines. Originally supplied as part of the Option Pack for Windows NT, they were subsequently integrated with Windows 2000 and Windows Server 2003. The current (Windows 2003) version is IIS 6.0 and includes servers for FTP, SMTP, NNTP and HTTP/HTTPS. Earlier versions also included a Gopher server.

Features

The web server itself can not directly perform server side processing but can delegate the task to ISAPI applications on the server. Microsoft provide a number of these including ones for Active Server Pages and ASP.NET. Third parties have provided support for PHP and Perl languages in the same way.

Compatibility

Internet Information Services is designed to run on Windows server operating systems. A restricted version that supports one web site and a limited number of connections is also supplied with Windows XP Professional.

Security

IIS has been attributed with a number of security exploits, most of which were in fact issues within the lesser used ISAPI filters. With Windows Server 2003 Microsoft finally elected to turn off all ISAPI handlers by default thereby giving the web server a much more secure "out of the box" configuration.

Microsoft has also changed the server account that IIS runs on. In versions of IIS before 6.0, all the features were run on the System account, allowing exploits to run wild on the system. Under 6.0 many of the processes have been brought under a Network Services account which has fewer privileges. In particular this means that if there is an exploit on that feature, it wouldn't necessarily compromise the entire system.

Competitors

Apache is the dominant software in the web server market and IIS's main competitor. Solaris Operating Environment/J2EE also competes in the enterprise web services arena.

External links

• Microsoft Internet Information Services homepage (http://www.microsoft.com/iis)
• Perl and Python for IIS (http://www.activestate.com/)