An Apache HTTP Server is more commonly called the Apache, which is web server software most notably for its key role in the growth of the World Wide Web. Apache became the first web server program to surpass the 100 million website milestone in the year 2009, and was the first real alternative to Netscape and has since rivaled many other Unix-based systems when it comes to performance and functionality. A vast majority of web servers that use Apache run a Unix-like operating system.

Apache is open software licensed under open source licensing, and is maintained and developed by a majority of developers in the open community. It is available for most operating systems, including Windows, OSX, Linux, GNU, FreeBSD, Solaris, OS/2, TPF, Novell, and eComStation. Apache is the most popular HTTP server software in use, with over 66 percent of all the busiest websites on the internet using the software in a February 2010 estimate.

Apache has an abundant list of features, many of which are extensions to the core functionality of the software. Some of these range from server-side programming to authentication schemes. Common language interfaces supported by Apache are Python, Perl, Tcl, and PHP. Other samples of features include SSL and TLS support, as well as a URL rewriter, filtering support, and custom file logs.

Because of virtual hosting, Apache can be allowed to serve many different websites. This will allow one machine to be able to server multiple websites at the same time. It is primarily used to serve dynamic web pages and static content on the internet. Many of the web applications that are designed for use on the web are expecting to work with the features that Apache provides. Programmers develop these applications on a machine that usually has a version of Apache installed so that they can do testing and previewing as it is created.

Apache is used for various tasks where content needs to be available in a secure way. If a person wants to share a file securely with someone, all the need is Apache running on the desktop. They will then place arbitrary files in Apache’s document root, which then can be shared to anyone wanting to look at the file. Apache’s main goal is to implement all standards of the web reliably and securely to everyone. The main competitors of Apache are Microsoft’s IIS and Sun Microsystems Java.