The Httpd Web Server, commonly referred to as Apache , is web server software renowned seeking playing a pivotal capacity in the commencing growth of the Set Big Web. In 2009 it became the first snare server software to surpass the 100 million website milestone. Apache was the beginning viable selection to the Netscape Communications Corporation web server (currently known as Seer iPlanet Entanglement Server), and has since evolved to rival other trap 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 open community of developers under the protection of the Apache Software Foundation. The application is elbow for a deviating selection 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 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 on the core functionality. These can choice from server-side programming language authenticate to authentication schemes. Some conventional words interfaces suffer Perl, Python, Tcl, and PHP. Popular authentication modules take in mod_access, mod_auth, mod_survive, and mod_auth_epitomize, the successor to mod_digest. A illustration of other features embrace SSL and TLS support (mod_ssl), a surrogate module (mod_representative), a URL rewriter (also known as a rewrite appliance, implemented supervised mod_rewrite), routine log files (mod_log_config), and filtering support (mod_comprehend and mod_ext_screen).
In demand compression methods on Apache allow for the superficial height module, mod_gzip, implemented to servants with reduction of the appraise (weight) of entanglement pages served over with HTTP. ModSecurity is an open begetter intrusion detection and interception locomotive exchange for net applications. Apache logs can be analyzed through a snare browser using sprung scripts such as AWStats/W3Perl or Visitors.
Essential hosting allows united Apache installation to one's duty innumerable diverse actual websites. On example, one machine with harmonious Apache ordination could simultaneously be in the service of www.example.com, www.test.com, examine47.test-server.test.com, etc.
Apache features configurable error messages, DBMS-based authentication databases, and constituents negotiation. It is also supported near sundry graphical operator interfaces (GUIs).
It supports open sesame authentication and digital certificate authentication. Apache has a built in search machine and an HTML authorizing tool and supports FTP.

Display


This portion does not cite any references or sources. Gladden improve amend this section through adding citations to principled sources. Unsourced figures may be challenged and removed. (October 2009)
Although the sheer cabal end of Apache is not to be the "fastest" entanglement server, Apache does entertain playing comparable to other "high-performance" web servers. A substitute alternatively of implementing a only architecture, Apache provides a variety of MultiProcessing Modules (MPMs) which concede Apache to run in a process-based, hybrid (modify and motif) or event-hybrid mode, to superior blend the demands of each separate infrastructure. This implies that the realm of possibilities of suitable MPM and the nullify configuration is important. Where compromises in performance lack to be made, the stratagem of Apache is to slash latency and advance throughput, associated to austerely handling more requests, in which case ensuring predictable and reliable processing of requests within reasonable time-frames.
The Apache reading considered past the Apache Fundamental as providing high-performance is the multi-threaded adaptation which mixes the put to use of several processes and diverse threads per process.
While this architecture works faster than the erstwhile multi-process based topology (because threads prepare a deign upper basic than processes), it does not match the performances of the event-based architecture provided via other servers, uncommonly when they change events with respective hand threads.
This dissimilarity can be beyond explained by the overhead that identical thread per interrelationship brings (as opposed to a couple of wage-earner threads per CPU, each processing many connection events). Each ease needs to uphold its own clamp, environment, and switching from one thread to another is also an valuable task for CPUs.