The Apache Software Foundation

 Please see the CHANGES_2.2 file, linked from the download page, for a full list of changes.  A condensed list, CHANGES_2.2.15 provides the complete list of changes since 2.2.14. A summary of security vulnerabilities which were addressed in the previous 2.2.14 and earlier releases is available:

  http://httpd.apache.org/security/vulnerabilities_22.html

Apache HTTP Server 2.2.15 is compatible with Apache Portable Runtime
(APR) versions 1.3 and 1.4, APR-util library version 1.3, and APR-iconv library version 1.2.  The most current releases should be used to address known security and platform bugs.  At the time of this httpd release, the recommended APR releases are:

  * Apache Portable Runtime (APR) library version 1.4.2 (bundled),
    or at minimum, version 1.3.12
  * ARR-util library version 1.3.9 (bundled)
  * APR-iconv library version 1.2.1 (only bundled in win32-src.zip)

Older releases of these libraries have known vulnerabilities or other defects affecting httpd.  For further information and downloads, visit:

  http://apr.apache.org/

Apache HTTP Server 2.2 offers numerous enhancements, bug fixes, and performance enhancements over the 2.0 codebase.  For an overview of new features introduced since 2.0 please see:

  http://httpd.apache.org/docs/2.2/new_features_2_2.html

This release builds upon and extends the httpd 2.0 API.  Modules written for httpd 2.0 will need to be recompiled in order to run with httpd 2.2, and may require minimal or no source code changes.

When upgrading or installing this version of httpd, please bear in mind that if you intend to use httpd with one of the threaded MPMs (other than the Prefork MPM), you must ensure that any modules you will be using (and the libraries they depend on) are thread-safe.

History

The Apache Server started as a fork (an independent development stream)
of the NCSA httpd, a Web server created by Rob McCool at the National Center for Supercomputing Applications.  Further development to the server ceased after McCool's departure from NCSA in 1994, so an online community of individuals was formed to support and enhance its software via email collaboration. The founding members of that community (the Apache Group) included Brian Behlendorf, Roy Fielding, Rob Hartill, David Robinson, Cliff Skolnick, Randy Terbush, Robert Thau, and Andrew Wilson.

Within less than a year of the Apache Group's formation, the Apache server surpassed NCSA httpd as the #1 server on the Internet.

In March 1999, members of the Apache Group formed The Apache Software Foundation to provide organizational, legal, and financial support for the Apache HTTP Server. An additional goal for the Foundation was to serve as a neutral, trusted platform for the development of community-driven software.

Growth, the "Apache Way"

Beyond the Apache HTTP Server, dozens of ASF projects – from build tools to Web services to cloud computing and more – lead the way in Open Source technology.

At the ASF, community plays a vital role in the collaborative development of consensus-driven, enterprise-grade solutions. The number of projects led by the Apache community has grown from the singular Apache HTTP Server at the ASF's inception in 1999 to nearly 140 projects today.

The ASF's commitment to fostering a collaborative approach to development has long served as a model for producing consistently high quality software and helping advance the future of open development. Through its leadership, robust community, and meritocratic process known as the "Apache Way", the ASF continues to gain recognition as one of the most successful influencers in Open Source.

Through the Apache Way, the ASF is able to spearhead new projects that meet the demands of the marketplace and help users achieve their business goals. With the Apache Incubator mentoring more projects than ever before, the ASF continues to meet the growing demand for quality Open Source products.

"Community Over Code": among the Foundation's core tenets is open collaboration through respectful, honest, technically-focused interaction. The ASF's success is testament to its outstanding community efforts that serve as best practices widely embraced by organizations and individuals alike.

"If it didn't happen on-list, it didn't happen": building upon the transparency-oriented culture of the Apache Group, whose collaboration took place on email lists, millions of messages are archived on Apache publicly-accessible mailing lists, documenting the ASF's achievements over the past decade.

"Meritocracy in Action": the ASF's tagline reflects an average of 10,000 code contributions (commits) made each month. The ASF is responsible for millions of lines of code by more than 2,000 ASF Committers and countless contributors across the Open Source landscape. Nearly 500 community-driven modules have been developed to extend functionality of the Apache HTTP Server alone.

Milestones

February 23, 1994: Individual patch authors around the world are invited to join the "new-httpd" mailing list to discuss enhancements and future releases of NCSA httpd. The Apache name was chosen for this new effort within the first few days of discussion, along with basic rules for email-based collaboration and a mission to replace the existing server with a standards-based, open source, and extensible software system.

March 15, 1994: Apache-style voting created (+1, 0, -1; with '-1' meaning 'no', '0' meaning 'neutral', and '+1' meaning 'yes.')

March 18, 1994: First Apache Group release (Apache 0.2)

Apache server v.1.0 was released in December 1995. Four years later, Apache HTTP Server v.1.3.0 was released, and rapidly becoming the most popular Web server on the planet.

Apache HTTP Server v.2.0 alpha was released in March 2000, with the first general availability release two years later. V.2.0 remained best-of-breed sever until the release of v.2.2.0 in December 2005, and is widely deployed across the Internet.

In February 2009, the Apache HTTP Server became the first Web server software in history to surpass the 100 million Website milestone.

The most current, best-of-breed, stable version of the Apache HTTP Server is v.2.2.14, released September 2009. Developers seeking to test new features and preview what will become stable Version 2.4 are able to do so today with the development of v.2.3.5.

Earlier this month, after ten years and more than forty revisions, the Apache HTTP Server v.1.3.x officially reached end of life status with the release of v.1.3.42. Future patches to v.1.3.x will be for critical security updates only.

The Apache HTTP Server remains the world's most beloved Web server, forming the backbone of nearly 70% of all sites on the Internet.

Availability

The Apache HTTP Server is available for a variety of operating systems, including Unix, Linux, GNU, FreeBSD, Netware, Solaris, Windows, Mac OS X, OS/2, TPF, and eCS. In addition, the Apache HTTP Server is redistributed through many proprietary software packages such as WebSphere, Oracle RDBMS, Kylix, NetWare, and Delphi, as well as numerous Linux distributions.

All ASF projects, including the Apache HTTP Server, are available free of charge under the Apache Software License v.2.0. To download, or for more information, visit http://httpd.apache.org/

About The Apache Software Foundation (ASF)

Established in 1999, the all-volunteer Foundation oversees more than seventy leading Open Source projects, including Apache HTTP Server — the world's most popular Web server software. Through The ASF's meritocratic process known as "The Apache Way," more than 300 individual Members and 2,000 Committers successfully collaborate to develop freely available enterprise-grade software, benefiting millions of users worldwide: thousands of software solutions are distributed under the Apache License; and the community actively participates in ASF mailing lists, mentoring initiatives, and ApacheCon, the Foundation's official user conference, trainings, and expo. The ASF is funded by individual donations and corporate sponsors including Facebook, Google, HP, Microsoft, Progress Software, SpringSource, and Yahoo! For more information, visit http://www.apache.org/.