Apache_HTTP

{{Infobox Software
| name = Apache HTTP Server
| logo = [[Image:ASF-logo.svg|250px]]
| developer = [[Apache Software Foundation]]
| latest release version = 2.2.6
| latest release date = [[September 6]] [[2007]]
| operating_system = [[Cross-platform]]
| genre = [[Web server]]
| license = [[Apache License]]
| website = http://httpd.apache.org/
}}

The '''Apache HTTP Server''', commonly referred to simply as '''Apache''', is a [[web server]] notable for playing a key role in the initial growth of the [[World Wide Web]]. Apache was the first viable alternative to the [[Netscape Communications Corporation]] web server (currently known as [[Sun Java System Web Server]]), and has since evolved to rival other Unix-based web servers in terms of functionality and performance. Since April 1996 Apache has been the most popular HTTP server on the [[World Wide Web]]; since March 2006 however it has experienced a steady decline of its market share,<ref>{{cite web |url=http://news.netcraft.com/archives/web_server_survey.html |title=Webservers' Market Shares |publisher=Netcraft |accessdate=2007-09-20}}</ref> lost mostly against Microsoft [[Internet Information Services]] and the [[.NET Framework|.NET]] platform. As of October 2007 Apache served 47.73% of all [[website]]s,<ref name=netcraft>{{cite web |url=http://news.netcraft.com/archives/web_server_survey.html |title=October 2007 |publisher=Netcraft |accessdate=2007-10-13}}</ref>
although there has been a steady spike in percentages recently. As of Nov 30, 2007 Apache served 50.76% of all [[website]]s according to [http://www.netcraft.com Netcraft]. This is a 3% increase since October 2007 while Microsoft has dropped 2%.
The project's name was chosen for two reasons:<ref>{{cite mailing list |url=http://www.mailarchives.org/list/apache-httpd-docs/msg/2001/00476 |title=Re: A Patchy Server and the FAQ |date=2001-05-12 |accessdate=2007-12-20 |mailinglist=apache-docs |last=Slive |first=Joshua}}</ref> out of respect for the Native American Indian tribe of [[Apache]] (Indé), well-known for their endurance and their skills in warfare,<ref>{{cite web |url=http://www.apache.org/foundation/faq.html#name |title=Frequently Asked Questions |publisher=The Apache Software Foundation |year=2007}}</ref> and due to the project's roots as a set of [[Software patch|patches]] to the codebase of NCSA HTTPd 1.3 - making it "a patchy" server.<ref>{{cite news |url=http://www.informationweek.com/showArticle.jhtml?articleID=196900465 |title=High Five: Meet Brian Behlendorf, CTO Of CollabNet |first=Charles |last=Babcock |date=2007-01-13 |work=[[InformationWeek]] |publisher=[[CMP Media]]}}</ref>

Apache is developed and maintained by an open community of developers under the auspices of the [[Apache Software Foundation]]. The application is available for a wide variety of [[operating system]]s, including [[Unix]], [[FreeBSD]], [[Linux]], [[Solaris (operating system)|Solaris]], [[Novell NetWare]], [[Mac OS X]], and [[Microsoft Windows]]. Released under the [[Apache License]], Apache is [[free software]] / [[open source software]].

== History ==
The first version of the Apache web server was created by [[Robert McCool]], who was heavily involved with the [[National Center for Supercomputing Applications]] web server, known simply as [[NCSA HTTPd]]. When Rob left NCSA in mid-1994, the development of httpd stalled, leaving a variety of patches for improvements circulating through e-mails.

Rob McCool was not alone in his efforts. Several other developers helped form the original "Apache Group": [[Brian Behlendorf]], [[Roy Fielding|Roy T. Fielding]], [[Rob Hartill]], David Robinson, Cliff Skolnick, Randy Terbush, Robert S. Thau, Andrew Wilson, Eric Hagberg, Frank Peters, and Nicolas Pioch.

Version 2 of the Apache server was a [[rewrite (programming)|substantial re-write]] of much of the Apache 1.x code, with a strong focus on further modularization and the development of a portability layer, the [[Apache Portable Runtime]]. The Apache 2.x core has several major enhancements over Apache 1.x. These include [[thread (computer science)|UNIX threading]], better support for non-Unix platforms (such as Microsoft Windows), a new Apache [[application programming interface|API]], and [[IPv6]] support.<ref>
{{cite manual |title=Apache HTTP Server Documentation|section=Overview of new features in Apache 2.2 |sectionurl=http://httpd.apache.org/docs/2.0/new_features_2_0.html |version=2.0 |publisher=The Apache Software Foundation |year=2007
|url=http://httpd.apache.org/docs/2.0}}</ref> The first [[alpha release]] of Apache 2 was in March 2000, with the first [[general availability release]] on [[6 April]] [[2002]].<ref>{{cite web |url=http://www.apacheweek.com/features/ap2 |title=Apache 2 Release |date=2002-04-06 |publisher=Apache Week |location=England}}</ref>

Version 2.2 introduced a new authorization API that allows for more flexibility. It also features improved cache modules and proxy modules.<ref>{{cite manual |title=Apache HTTP Server Documentation|section=Overview of new features in Apache 2.2 |sectionurl=http://httpd.apache.org/docs/2.2/new_features_2_2.html |version=2.2 |publisher=The Apache Software Foundation |year=2007
|url=http://httpd.apache.org/docs/2.2}}</ref>

== Features ==
Apache supports a variety of features, many implemented as compiled modules which extend the core functionality. These can range from server-side programming language support to authentication schemes. Some common language interfaces support [[mod_perl]], [[mod_python]], [[Tcl]], and [[PHP]]. Popular authentication modules include mod_access, mod_auth, and mod_digest. A sample of other features include [[Secure Sockets Layer|SSL]] and [[Transport Layer Security|TLS]] support (mod_ssl), a [[proxy server|proxy]] module, a useful URL rewriter (also known as a [[rewrite engine]], implemented under mod_rewrite), custom log files (mod_log_config), and filtering support (mod_include and mod_ext_filter).

Popular compression methods on Apache include the external extension module, mod_gzip, implemented to help with reduction of the size (weight) of web pages served over [[HTTP]]. Web-based [[blogging]] [[software]] such as [[Wordpress]], which run on Apache, are capable of allowing pages served to be reduced greatly in size through implementations of mod_gzip coupled with [[PHP]], with the help of PHP's [http://www.php.net/gzdeflate gzdeflate] and/or other methods. [http://www.cheb.com.au/making-wordpress-faster-with-php-mod_gzip/]

Apache logs can be analyzed through a web browser using free scripts such as [[AWStats]]/[[W3Perl]] or [[Visitors (program)|Visitors]].

[[Virtual hosting]] allows one Apache installation to serve many different actual websites. For example, one machine, with one Apache installation could simultaneously serve www.example.com, www.test.com, test47.test-server.test.com, etc.

Apache features configurable error messages, [[Database management system|DBMS]]-based authentication databases, and [[content negotiation]]. It is also supported by several [[graphical user interface]]s (GUIs) which permit easier, more intuitive configuration of the server.

== Usage ==
Apache is primarily used to serve both static content and [[dynamic Web page]]s on the World Wide Web. Many [[web application]]s are designed expecting the environment and features that Apache provides.

Apache is the web server component of the popular [[LAMP (software bundle)|LAMP]] web server application stack, alongside [[MySQL]], and the [[PHP]]/[[Perl]]/[[Python (programming language)|Python]] programming languages.

Apache is redistributed as part of various proprietary software packages including the [[Oracle Database]] or the [[IBM WebSphere]] [[application server]]. Mac OS X integrates Apache as its built-in web server and as support for its [[WebObjects]] application server. It is also supported in some way by [[Borland]] in the [[Kylix programming tool|Kylix]] and [[Borland Delphi|Delphi]] development tools. Apache is included with Novell NetWare 6.5, where it is the default web server.

Apache is used for many other tasks where content needs to be made available in a secure and reliable way. One example is sharing files from a personal computer over the Internet. A user who has Apache installed on their desktop can put arbitrary files in the Apache's document root which can then be shared.

Programmers developing web applications often use a locally installed version of Apache in order to preview and test code as it is being developed.

Microsoft [[Internet Information Services]] (IIS) is the main competitor to Apache, trailed by [[Sun Microsystems]]' [[Sun Java System Web Server]] and a host of other applications such as [[Zeus Web Server]].

== License ==
{{main|Apache License}}

The [[software license]] under which software from the Apache Foundation is distributed is a distinctive part of the Apache HTTP Server's history and presence in the open source software community. The Apache License allows for the distribution of both open and [[closed source]] [[fork (software development)|derivation]]s of the source code.

The [[Free Software Foundation]] does not consider the Apache License to be compatible with version 2 of the [[GNU General Public License]] (GPL) in that software licensed under the Apache License cannot be integrated with software that is distributed under the GPL:

{{quote|This is a free software license but it is incompatible with the GPL. The Apache Software License is incompatible with the GPL because it has a specific requirement that is not in the GPL: it has certain patent termination cases that the GPL does not require. We don't think those patent termination cases are inherently a bad idea, but nonetheless they are incompatible with the GNU GPL.|http://www.gnu.org/philosophy/license-list.html}}
However, version 3 of the GPL includes a provision (Section 7e) which allows it to be compatible with licenses that have patent retaliation clauses, including the Apache License.

The name ''Apache'' is a registered [[trademark]] and may only be used with the trademark holder's express permission.<ref>{{cite web |url=http://www.apache.org/foundation/licence-FAQ.html#Marks |title=Apache License and Distribution FAQ |publisher=The Apache Software Foundation |year=2007}}</ref>

== See also ==
{{portal|Free software|Free Software Portal Logo.svg}}

* [[Comparison of web servers]]
* [[.htaccess]]
* [[Stronghold (software)]]
* [[ApacheBench]]
* [[POSSE project]]

== References ==
{{Reflist|1}}

== External links ==
* [http://httpd.apache.org/ Apache HTTP Server official website]
* [http://www.apachenews.org/ Apache News]
* [http://wiki.apache.org/ Apache Wiki]
* [http://www.apachelounge.com Apache Lounge]: Apache2 on [[Windows]]
* [http://prefetch.net/articles/debuggingapache.html Debugging Apache web server problems]
* [http://httpd.apache.org/docs/2.2/misc/rewriteguide.html URL rewriting guide]

{{apache}}

[[Category:Unix software]]
[[Category:Apache Software Foundation|HTTP Server]]
[[Category:Free web server software]]

[[bs:Apache HTTP server]]
[[bg:Apache]]
[[ca:Servidor HTTP Apache]]
[[cs:Apache HTTP Server]]
[[da:Apache (webserver)]]
[[de:Apache HTTP Server]]
[[el:Apache HTTP εξυπηρετητής]]
[[es:Servidor HTTP Apache]]
[[eo:Retservilo Apache]]
[[eu:Apache HTTP zerbitzaria]]
[[fa:آپاچی (نرم‌افزار)]]
[[fr:Apache HTTP Server]]
[[ko:아파치 웹 서버]]
[[hr:Apache HTTP poslužitelj]]
[[id:Apache HTTP Server]]
[[ia:Apache HTTP Servitor]]
[[it:Apache HTTP Server]]
[[he:Apache HTTP Server]]
[[lt:Apache HTTP Serveris]]
[[ms:Apache]]
[[nl:Apache (webserver)]]
[[ja:Apache HTTP Server]]
[[no:Apache (webserver)]]
[[nn:Apache]]
[[uz:Apache Server]]
[[pl:Apache (serwer)]]
[[pt:Servidor Apache]]
[[ro:Apache]]
[[ru:Apache]]
[[sk:Apache HTTP Server]]
[[sl:Spletni strežnik Apache]]
[[sr:Veb server Apač]]
[[fi:Apache (palvelinohjelma)]]
[[sv:Apache HTTP Server]]
[[ta:அப்பாச்சி இணைய வழங்கி]]
[[th:อะแพชี เว็บเซิร์ฟเวอร์]]
[[vi:Apache]]
[[tr:Apache HTTP Sunucusu]]
[[uk:Apache]]
[[zh:Apache]]