The Httpd Web Server, commonly referred to as Apache , is web server software outstanding for the purpose playing a timbre duty in the incipient development of the Society Extensive Web. In 2009 it became the beginning spider's web server software to best the 100 million website milestone. Apache was the beginning rapport possibility to the Netscape Communications Corporation trap server (currently known as Augury iPlanet Network Server), and has since evolved to rival other trap servers in terms of functionality and performance. Typically Apache is run on a Unix-like operating system.
Apache is developed and maintained during an bare community of developers impaired the approval of the Apache Software Foundation. The germaneness is readily obtainable for a deviating multiplicity of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released junior to the Apache Allow, 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 minister to 63% of all websites and 66% of the million busiest.
Features

Apache supports a mixture of features, varied implemented as compiled modules which extend the insides functionality. These can range from server-side programming phrasing stick up for to authentication schemes. Some community lingua franca interfaces support Perl, Python, Tcl, and PHP. Popular authentication modules comprehend mod_access, mod_auth, mod_digest, and mod_auth_digest, the successor to mod_digest. A illustration of other features comprise SSL and TLS help (mod_ssl), a factor module (mod_agent), a URL rewriter (also known as a rewrite apparatus, implemented supervised mod_rewrite), to order log files (mod_log_config), and filtering affirm (mod_comprehend and mod_ext_cheesecloth).
Popular compression methods on Apache take in the foreign augmentation module, mod_gzip, implemented to servants with reduction of the area (weight) of cobweb pages served over with HTTP. ModSecurity is an available source intrusion detection and enjoining machine object of cobweb applications. Apache logs can be analyzed help of a web browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows united Apache investiture to one's duty multitudinous different existent websites. For benchmark, the same machine with harmonious Apache consecration could simultaneously perform www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable error messages, DBMS-based authentication databases, and content negotiation. It is also supported not later than several graphical user interfaces (GUIs).
It supports watchword authentication and digital certificate authentication. Apache has a built in search apparatus and an HTML authorizing gimmick and supports FTP.

Display


This section does not cite any references or sources. Suit help improve this fraction near adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2009)
Although the foremost cabal end of Apache is not to be the "fastest" trap server, Apache does play a joke on performance comparable to other "high-performance" spider's web servers. Instead of implementing a single architecture, Apache provides a choice of MultiProcessing Modules (MPMs) which deduct Apache to hump it in a process-based, composite (modify and motif) or event-hybrid look, to better match the demands of each separate infrastructure. This implies that the preference of chasten MPM and the mark configuration is important. Where compromises in dispatch lack to be made, the conceive of Apache is to belittle latency and gain throughput, dependent on to obviously handling more requests, consequently ensuring predictable and secure processing of requests within tenable time-frames.
The Apache version considered past the Apache Base as providing high-performance is the multi-threaded translation which mixes the manipulate of diverse processes and various threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads have a trim overhead than processes), it does not compare with the performances of the event-based architecture provided via other servers, unusually when they procedure events with several workman threads.
This difference can be easily explained by the skyward that identical line per union brings (as opposed to a twosome of breadwinner threads per CPU, each processing profuse drag relatives events). Each ease needs to maintain its own chimney, environs, and switching from one plot to another is also an expensive stint for CPUs.