Web servers

Web servers are software installations on existing server operating system platforms:

• Microsoft Internet Information Service (IIS)
• Apache Server
• Oracle iPlanet
• NginX
• Google Web Service (GWS)

Like browsers, web servers can extend their functionality with modules

• Active Server Page (ASP)
• Structured Query Language (SQL)
• Linux, Apache, MySQL, PHP (LAMP)

Web server software is usually installed on top of an existing server operating system.

There are few web server systems in use globally, the main ones being from Microsoft and Apache.

Microsoft produces Internet Information Service (IIS) as a standard role of both Windows server and Windows desktop operating systems. Typically, the role has to be added as a new feature, as it is not installed by default.

Apache HTTP Server is an open-source development, overseen by the Apache Software Foundation, and is designed to be multi-platform capable in that it can run on UNIX, Linux, Apple, and Microsoft operating systems.

Microsoft and Apache control the largest share of web server systems, but there are others available, such as iPlanet from Oracle Systems, and NginX from NginX Inc. Google also operate their own in-house built web server called GWS (Google Web Server) of which little is known, but it appears to be a Linux-based design.

Like browsers, web servers can have their capabilities extended via plug-ins, although these are more widely known as modules in this environment.

One of the most popular modules to be added to a web server is one that can handle server-side scripts to allow for dynamic web page creation. Microsoft’s module for this is called ASP (Active Server Page), whereas the open-source option is called PHP (Pre-Hypertext Pre-processor). Other modules can include SQL and cryptographic tools, amongst others.