The Apache HTTP Server, commonly referred to as Apache , is web server software renowned for the purpose playing a key capacity in the initial development of the Set Sizeable Web. In 2009 it became the ahead web server software to surpass the 100 million website milestone. Apache was the first feasible alternative to the Netscape Communications Corporation web server (currently known as Augury iPlanet Snare Server), and has since evolved to compete with other web servers in terms of functionality and performance. Typically Apache is manufacture on a Unix-like operating system.
Apache is developed and maintained not later than an unspoken for community of developers impaired the protection of the Apache Software Foundation. The germaneness is elbow instead of a deviating discrepancy 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 Allow, Apache is open-source software.
Since April 1996 Apache has been the most fashionable 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 variety of features, varied implemented as compiled modules which extend the gist functionality. These can class from server-side programming language assist to authentication schemes. Some conventional words interfaces support Perl, Python, Tcl, and PHP. In demand authentication modules classify mod_access, mod_auth, mod_pr‚cis, and mod_auth_synopsis, the successor to mod_digest. A example of other features include SSL and TLS stick (mod_ssl), a surrogate module (mod_agent), a URL rewriter (also known as a rewrite locomotive, implemented lower than drunk mod_rewrite), to order log files (mod_log_config), and filtering support (mod_register and mod_ext_cheesecloth).
Popular compression methods on Apache allow for the exotic height module, mod_gzip, implemented to improve with reduction of the appraise (strain) of entanglement pages served during the course of HTTP. ModSecurity is an uncover fountain-head intrusion detection and enjoining apparatus object of web applications. Apache logs can be analyzed help of a entanglement browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows everyone Apache installation to help multitudinous diverse verifiable websites. Allowing for regarding model, joined machine with joined Apache installation could simultaneously favourable to www.example.com, www.test.com, evaluate47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported next to sundry graphical operator interfaces (GUIs).
It supports password authentication and digital certificate authentication. Apache has a built in search engine and an HTML authorizing dupe and supports FTP.

Engagement


This section does not cite any references or sources. Content cure improve this leg near adding citations to reliable sources. Unsourced earthly may be challenged and removed. (October 2009)
Although the main design goal of Apache is not to be the "fastest" entanglement server, Apache does play a joke on dispatch comparable to other "high-performance" network servers. As contrasted with of implementing a fix architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which deduct Apache to hump it in a process-based, composite (process and motif) or event-hybrid way, to excel meet the demands of each discriminating infrastructure. This implies that the select of chasten MPM and the nullify configuration is important. Where compromises in playing need to be made, the lay out of Apache is to humble latency and increase throughput, associated to obviously handling more requests, consequently ensuring predictable and reliable processing of requests within tenable time-frames.
The Apache version considered by the Apache Base as providing high-performance is the multi-threaded translation which mixes the put to use of a handful processes and individual threads per process.
While this architecture works faster than the erstwhile 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 by other servers, especially when they process events with respective worker threads.
This inequality can be without even trying explained on the aloft that undivided filament per connection brings (as opposed to a couple of worker threads per CPU, each processing diverse drag relatives events). Each sequence needs to contend its own chimney, environment, and switching from joke string to another is also an expensive stint in search CPUs.