Linux

Pronounced lee-nucks. Linux is a computer operating system and its kernel. It is one of the most prominent examples of free software and of open-source development: unlike proprietary operating systems such as Windows and Mac OS, all of its underlying source code is available to the public and anyone can freely use, modify, and redistribute it.

In the narrowest sense, the term Linux refers to the Linux kernel, but it is commonly used to describe entire Unix-like operating systems (also known as GNU/Linux) that are based on the Linux kernel combined with libraries and tools from the GNU project and other sources. Most broadly, a Linux distribution bundles large quantities of application software with the core system, and provides more user-friendly installation and upgrades.

Initially, Linux was primarily developed and used by individual enthusiasts. Since then, Linux has gained the support of major corporations such as IBM, Hewlett-Packard, and Novell for use in servers and is gaining popularity in the desktop market. Proponents and analysts attribute this success to its vendor independence, low cost, security, and reliability.

Linux was originally developed for Intel 386 microprocessors and now supports all popular computer architectures (and several obscure ones). It is deployed in applications ranging from embedded systems (such as mobile phones and personal video recorders) to personal computers to supercomputers.

Apache Web Server

Apache is an open-source (source code is freely available and can be shared) HTTP Web server software. It is currently the most popular web server on the Net. It is usually run on Unix operating system versions like Linux or BSD, but it can also be run on Windows. It is a full-featured server with many powerful add-ons freely available. Apache’s major competitor is Microsoft®’s IIS.

PHP

PHP: Hypertext Preprocessor is an open source server side programming language extensively used for web scripts and to process data passed via the Common Gateway Interface from HTML forms etc. PHP can be written as scripts that reside on the server and may produce HTML output that downloads to the web browser. Alternatively, PHP can be embedded within HTML pages that are then saved with a .php file extension. The PHP sections of the page are then parsed by the PHP engine on the server and the PHP code stripped out before the page is downloaded to the web browser.

The name is a bit of a programming joke (if there is such a thing) since it’s a recursive acronym i.e. the P in PHP stands for PHP.