The Httpd Web Server, commonly referred to as Apache , is spider's web server software renowned seeking playing a pivotal duty in the introductory success of the Set Wide Web. In 2009 it became the principal web server software to surpass the 100 million website milestone. Apache was the chief practicable selection to the Netscape Communications Corporation trap server (currently known as Augury iPlanet Web Server), and has since evolved to contest 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 open community of developers impaired the auspices of the Apache Software Foundation. The utilization is elbow for 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 impaired the Apache Accredit, Apache is open-source software.
Since April 1996 Apache has been the most normal 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 breed of features, many implemented as compiled modules which extend the core functionality. These can range from server-side programming lingo support to authentication schemes. Some inferior words interfaces support Perl, Python, Tcl, and PHP. Trendy authentication modules classify mod_access, mod_auth, mod_digest, and mod_auth_digest, the successor to mod_digest. A representation of other features comprise SSL and TLS support (mod_ssl), a surrogate module (mod_proxy), a URL rewriter (also known as a rewrite engine, implemented supervised mod_rewrite), custom log files (mod_log_config), and filtering support (mod_include and mod_ext_screen).
Popular compression methods on Apache allow for the external dimensions module, mod_gzip, implemented to help with reduction of the size (weight) of web pages served over with HTTP. ModSecurity is an available begetter intrusion detection and enjoining machine exchange for web applications. Apache logs can be analyzed help of a web browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Virtual hosting allows everyone Apache consecration to one's duty uncountable different actual websites. Allowing for regarding example, joined mechanism with harmonious Apache swearing-in could simultaneously serve www.example.com, www.test.com, check up on47.test-server.test.com, etc.
Apache features configurable slip-up messages, DBMS-based authentication databases, and tranquillity negotiation. It is also supported not later than sundry graphical consumer interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search locomotive and an HTML authorizing tool and supports FTP.

Performance


This fraction does not cite any references or sources. Gladden help amend this division by adding citations to principled sources. Unsourced material may be challenged and removed. (October 2009)
Although the main cabal aspiration of Apache is not to be the "fastest" spider's web server, Apache does entertain dispatch comparable to other "high-performance" network servers. As contrasted with of implementing a single architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which permit Apache to hump it in a process-based, combination (deal with and filament) or event-hybrid way, to think twice match the demands of each discriminating infrastructure. This implies that the select of correct MPM and the mark configuration is important. Where compromises in performance desperate straits to be made, the conceive of Apache is to belittle latency and advance throughput, dependent on to obviously handling more requests, consequently ensuring in concordance and secure processing of requests within tenable time-frames.
The Apache translation considered past the Apache Fundamental as providing high-performance is the multi-threaded translation which mixes the utilize consume of diverse processes and various threads per process.
While this architecture works faster than the erstwhile multi-process based topology (because threads set up a deign outlay than processes), it does not compare with the performances of the event-based architecture provided by other servers, especially when they procedure events with respective workman threads.
This inequality can be smoothly explained on the overhead that one line per union brings (as opposed to a four of worker threads per CPU, each processing diverse connection events). Each ease needs to maintain its own clamp, environs, and switching from joke thread to another is also an valuable stint in compensation CPUs.