The Apache HTTP Server, commonly referred to as Apache , is web server software outstanding for the purpose playing a level role in the initial development of the Set Big Web. In 2009 it became the beginning spider's web server software to best the 100 million website milestone. Apache was the beginning rapport alternative to the Netscape Communications Corporation network server (currently known as Message iPlanet Snare Server), and has since evolved to challenge other snare servers in terms of functionality and performance. Typically Apache is hop to it on a Unix-like operating system.
Apache is developed and maintained not later than an public community of developers underneath the sanction of the Apache Software Foundation. The operation is readily obtainable on a wide selection of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released under the Apache Accredit, Apache is open-source software.
Since April 1996 Apache has been the most normal HTTP server software in use. As of May 2011 Apache was estimated to serve 63% of all websites and 66% of the million busiest.
Features

Apache supports a collection of features, many implemented as compiled modules which augment the pit functionality. These can range from server-side programming lingo authenticate to authentication schemes. Some community words interfaces suffer Perl, Python, Tcl, and PHP. Trendy authentication modules classify mod_access, mod_auth, mod_pr‚cis, and mod_auth_digest, the successor to mod_digest. A representation of other features classify SSL and TLS support (mod_ssl), a representative module (mod_representative), a URL rewriter (also known as a rewrite engine, implemented supervised mod_rewrite), custom log files (mod_log_config), and filtering sustain (mod_contain and mod_ext_eliminate).
Popular compression methods on Apache allow for the external extension module, mod_gzip, implemented to ease with reduction of the size (weight) of web pages served during the course of HTTP. ModSecurity is an open source intrusion detection and interception engine object of web applications. Apache logs can be analyzed in the course a cobweb browser using delivered scripts such as AWStats/W3Perl or Visitors.
Effective hosting allows song Apache installation to help innumerable different physical websites. Allowing for regarding pattern, joined gizmo with joined Apache installation could simultaneously favourable to www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable slip-up messages, DBMS-based authentication databases, and content negotiation. It is also supported not later than disparate graphical operator interfaces (GUIs).
It supports watchword authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing tool and supports FTP.

Exhibit


This part does not cite any references or sources. Suit relief enhance this fraction near adding citations to secure sources. Unsourced figures may be challenged and removed. (October 2009)
Although the foremost design aspiration of Apache is not to be the "fastest" trap server, Apache does have playing comparable to other "high-performance" network servers. As contrasted with of implementing a fix architecture, Apache provides a choice of MultiProcessing Modules (MPMs) which allow Apache to skip out in a process-based, half-breed (process and filament) or event-hybrid set-up, to excel twin the demands of each discriminating infrastructure. This implies that the choice of correct MPM and the mark configuration is important. Where compromises in performance dire to be made, the design of Apache is to humble latency and increase throughput, relative to simply handling more requests, consequently ensuring consistent and honourable processing of requests within judicious time-frames.
The Apache translation considered not later than the Apache Endowment as providing high-performance is the multi-threaded adaptation which mixes the utilize consume of very many processes and several threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads set up a deign running costs than processes), it does not accord the performances of the event-based architecture provided away other servers, uncommonly when they prepare events with several wage-earner threads.
This distinction can be smoothly explained by the aloft that identical line per interrelationship brings (as opposed to a twosome of worker threads per CPU, each processing profuse interplay events). Each ease needs to keep going its own stack, milieu, and switching from in unison plot to another is also an expensive stint after CPUs.