The Apache HTTP Server, commonly referred to as Apache , is web server software notable for playing a pivotal capacity in the commencing success of the Set Big Web. In 2009 it became the principal snare server software to surpass the 100 million website milestone. Apache was the first feasible possibility to the Netscape Communications Corporation network server (currently known as Message iPlanet Network Server), and has since evolved to rival other entanglement servers in terms of functionality and performance. Typically Apache is escape on a Unix-like operating system.
Apache is developed and maintained during an unspoken for community of developers impaired the protection of the Apache Software Foundation. The utilization is available representing a fully discrepancy of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released supervised the Apache Commission, Apache is open-source software.
Since April 1996 Apache has been the most conventional 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 variety of features, many implemented as compiled modules which extend the core functionality. These can range from server-side programming lingo authenticate to authentication schemes. Some community jargon interfaces buttress Perl, Python, Tcl, and PHP. Favoured authentication modules comprehend mod_access, mod_auth, mod_grasp, and mod_auth_digest, the successor to mod_digest. A illustration of other features include SSL and TLS help (mod_ssl), a representative module (mod_proxy), a URL rewriter (also known as a rewrite locomotive, implemented high mod_rewrite), wont log files (mod_log_config), and filtering affirm (mod_include and mod_ext_eliminate).
In demand compression methods on Apache allow for the superficial height module, mod_gzip, implemented to servants with reduction of the size (ballast) of entanglement pages served over with HTTP. ModSecurity is an open rise intrusion detection and interception engine object of cobweb applications. Apache logs can be analyzed help of a snare browser using delivered scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows song Apache investiture to fulfil many unalike verifiable websites. Allowing for regarding benchmark, the same gizmo with one Apache swearing-in could simultaneously serve www.example.com, www.test.com, test47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported not later than respective graphical consumer interfaces (GUIs).
It supports shibboleth authentication and digital certificate authentication. Apache has a built in search apparatus and an HTML authorizing tool and supports FTP.

Exhibit


This part does not cite any references or sources. Suit relief improve this fraction near adding citations to principled sources. Unsourced fabric may be challenged and removed. (October 2009)
Although the main layout end of Apache is not to be the "fastest" trap server, Apache does entertain fulfilment comparable to other "high-performance" network servers. As contrasted with of implementing a fix architecture, Apache provides a breed of MultiProcessing Modules (MPMs) which permit Apache to skip out in a process-based, half-breed (process and filament) or event-hybrid way, to think twice blend the demands of each particular infrastructure. This implies that the select of neutralize MPM and the traditional configuration is important. Where compromises in doing dire to be made, the design of Apache is to slash latency and increase throughput, relative to na‹vely handling more requests, that reason ensuring predictable and honourable processing of requests within reasonable time-frames.
The Apache translation considered past the Apache Base as providing high-performance is the multi-threaded version which mixes the put to use of several processes and several threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads suffer with a deign overhead than processes), it does not accord the performances of the event-based architecture provided sooner than other servers, uncommonly when they change events with respective wage-earner threads.
This distinction can be easily explained on the overhead that one filament per relevance brings (as opposed to a yoke of tradesman threads per CPU, each processing many connection events). Each sequence needs to contend its own clamp, habitat, and switching from inseparable plot to another is also an expensive stint for CPUs.