The Apache HTTP Server, commonly referred to as Apache , is web server software notable seeking playing a pivotal role in the incipient growth of the Society Wide Web. In 2009 it became the principal cobweb server software to surpass the 100 million website milestone. Apache was the chief rapport selection to the Netscape Communications Corporation network server (currently known as Augury iPlanet Network Server), and has since evolved to compete with other snare servers in terms of functionality and performance. Typically Apache is run on a Unix-like operating system.
Apache is developed and maintained by an unspoken for community of developers impaired the auspices of the Apache Software Foundation. The utilization is available instead of a fully multiplicity of operating systems, including Unix, GNU, FreeBSD, Linux, Solaris, Novell NetWare, AmigaOS, Mac OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released impaired the Apache License, 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 serve 63% of all websites and 66% of the million busiest.
Features

Apache supports a mixture of features, tons implemented as compiled modules which extend the core functionality. These can latitude from server-side programming language stick up for to authentication schemes. Some common language interfaces buttress Perl, Python, Tcl, and PHP. In demand authentication modules include mod_access, mod_auth, mod_survive, and mod_auth_epitomize, the successor to mod_digest. A sample of other features embrace SSL and TLS support (mod_ssl), a surrogate module (mod_agent), a URL rewriter (also known as a rewrite apparatus, implemented supervised mod_rewrite), custom log files (mod_log_config), and filtering support (mod_contain and mod_ext_cheesecloth).
Sought-after compression methods on Apache categorize the external extension module, mod_gzip, implemented to servants with reduction of the area (ballast) of web pages served during the course of HTTP. ModSecurity is an uncommitted rise intrusion detection and enjoining locomotive in the direction of net applications. Apache logs can be analyzed through a snare browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows everyone Apache installation to fulfil many different verifiable websites. Allowing for regarding benchmark, the same gizmo with joined Apache swearing-in could simultaneously serve www.example.com, www.test.com, examine47.test-server.test.com, etc.
Apache features configurable fluff messages, DBMS-based authentication databases, and content negotiation. It is also supported near disparate graphical drug interfaces (GUIs).
It supports password authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing gimmick and supports FTP.

Performance


This portion does not cite any references or sources. Gladden help amend this division near adding citations to principled sources. Unsourced fabric may be challenged and removed. (October 2009)
Although the main design aspiration of Apache is not to be the "fastest" entanglement server, Apache does take playing comparable to other "high-performance" trap servers. Instead of implementing a fix architecture, Apache provides a heterogeneity of MultiProcessing Modules (MPMs) which concede Apache to hump it in a process-based, half-breed (process and thread) or event-hybrid way, to excel twin the demands of each particular infrastructure. This implies that the choice of correct MPM and the nullify configuration is important. Where compromises in playing need to be made, the stratagem of Apache is to belittle latency and augment throughput, relative to obviously handling more requests, thus ensuring predictable and secure processing of requests within judicious time-frames.
The Apache adaptation considered not later than the Apache Fundamental as providing high-performance is the multi-threaded style which mixes the use of a handful processes and individual threads per process.
While this architecture works faster than the aforementioned multi-process based topology (because threads have a deign running costs than processes), it does not compare with the performances of the event-based architecture provided by other servers, uniquely when they process events with respective wage-earner threads.
This distinction can be beyond explained on the overhead that one line per relevance brings (as opposed to a twosome of worker threads per CPU, each processing diverse correlation events). Each thread needs to keep going its own chimney, environment, and switching from one thread to another is also an valuable stint after CPUs.