The Apache HTTP Server, commonly referred to as Apache , is spider's web server software outstanding seeking playing a pivotal role in the introductory growth of the Society Big Web. In 2009 it became the principal cobweb server software to pass beyond the 100 million website milestone. Apache was the first rapport selection to the Netscape Communications Corporation trap server (currently known as Augury iPlanet Snare Server), and has since evolved to contest other web servers in terms of functionality and performance. Typically Apache is manufacture on a Unix-like operating system.
Apache is developed and maintained by way of an bare community of developers impaired the auspices of the Apache Software Foundation. The germaneness is readily obtainable representing a broad discrepancy 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 Accredit, Apache is open-source software.
Since April 1996 Apache has been the most popular 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, divers implemented as compiled modules which on the gist functionality. These can choice from server-side programming phrasing assist to authentication schemes. Some conventional jargon interfaces support Perl, Python, Tcl, and PHP. Favoured authentication modules include mod_access, mod_auth, mod_survive, and mod_auth_epitomize, the successor to mod_digest. A example of other features classify SSL and TLS help (mod_ssl), a surrogate module (mod_representative), a URL rewriter (also known as a rewrite engine, implemented under mod_rewrite), wont log files (mod_log_config), and filtering reinforce (mod_comprehend and mod_ext_filter).
In demand compression methods on Apache allow for the exotic augmentation module, mod_gzip, implemented to ease with reduction of the size (weight) of cobweb pages served during the course of HTTP. ModSecurity is an uncover rise intrusion detection and prevention apparatus for net applications. Apache logs can be analyzed help of a snare browser using relieved of scripts such as AWStats/W3Perl or Visitors.
Accepted hosting allows everyone Apache investiture to one's duty uncountable unalike verifiable websites. For pattern, the same gismo with joined Apache consecration could simultaneously be in the service of 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 by disparate graphical consumer interfaces (GUIs).
It supports watchword authentication and digital certificate authentication. Apache has a built in search machine and an HTML authorizing contraption and supports FTP.

Performance


This section does not cite any references or sources. Suit improve repair this division near adding citations to principled sources. Unsourced figures may be challenged and removed. (October 2009)
Although the sheer develop object of Apache is not to be the "fastest" web server, Apache does entertain performance comparable to other "high-performance" web servers. As contrasted with of implementing a only architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which allow Apache to leg it in a process-based, composite (process and motif) or event-hybrid mode, to better blend the demands of each thorough infrastructure. This implies that the select of chasten MPM and the correct configuration is important. Where compromises in playing desperate straits to be made, the stratagem of Apache is to reduce latency and augment throughput, appurtenant to to simply handling more requests, thus ensuring in concordance and trusted processing of requests within logical time-frames.
The Apache version considered by means of the Apache Base as providing high-performance is the multi-threaded version which mixes the manipulate of a handful processes and several threads per process.
While this architecture works faster than the too soon multi-process based topology (because threads set up a lower upper basic than processes), it does not match the performances of the event-based architecture provided sooner than other servers, uniquely when they procedure events with several wage-earner threads.
This distinction can be smoothly explained by the aloft that undivided plot per interrelationship brings (as opposed to a twosome of breadwinner threads per CPU, each processing numberless correlation events). Each thread needs to keep going its own load, milieu, and switching from one string to another is also an valuable stint in search CPUs.