Windows Server 2003 (sometimes referred to as Win2K3) is a server operating system produced by Microsoft, released on April 24, 2003. An updated version, Windows Server 2003 R2, was released to manufacturing on December 6, 2005. Its successor, Windows Server 2008, was released on February 4, 2008. It is based on Windows XP, basically becoming an enhanced version of XP. According to Microsoft, Windows Server 2003 is more scalable and delivers better performance than its predecessor, Windows 2000.
Windows Server 2003 Web is meant for building and hosting Web applications, Web pages, and XML web services. It is designed to be used primarily as an IIS 6.0 Web server and provides a platform for developing and deploying XML Web services and applications that use ASP.NET technology, a key part of the .NET Framework. Terminal Services is not included on Web Edition. However, Remote Desktop for Administration is available. Only 10 concurrent file-sharing connections are allowed at any moment. It is not possible to install Microsoft SQL Server and Microsoft Exchange software in this edition without installing Service Pack 1. Despite supporting XML Web services and ASP.NET, UDDI cannot be deployed on Windows Server 2003 Web. The .NET Framework version 2.0 is not included with Windows Server 2003 Web, but can be installed as a separate update from Windows Update.
Windows Server 2003 Web supports a maximum of 2 physical processors and a maximum of 2GB of RAM. However, an instance of Windows Server 2003 Web cannot act as a domain controller. It is the only edition of Windows Server 2003 that does not require Client Access Licenses when used as the internet facing server front-end for Internet Information Services and Windows Server Update Services. When using it for storage or as a back-end with another remote server as the front-end, CALs may still be required.