History and name
The first version of the Apache web server software was created by Robert McCool, who was heavily involved with the National Center for Supercomputing Applications web server, known simply as NCSA HTTPd. When McCool left NCSA in mid-1994, the development of httpd stalled, leaving a variety of patches for improvements circulating through e-mails. These patches were provided by a number of other developers besides McCool, and they thus helped to form the original "Apache Group".
There have been two explanations of the project's name. According to the Apache Foundation, the name was chosen out of respect for the Native American tribe of Apache (Indé), well-known for their endurance and their skills in warfare. However, the original FAQ on the Apache Server project's website, from 1996 to 2001, claimed that "The result after combining [the NCSA httpd patches] was a patchy server. The first explanation was supported at an Apache Conference and in an interview in 2000 by Brian Behlendorf, who said that the name connoted "Take no prisoners. Be kind of aggressive and kick some ass". Behlendorf then contradicted this in a 2007 interview, stating that "The Apache server isn't named in honor of Geronimo's tribe" but that so many revisions were sent in that "the group called it 'a patchy Web server'". Both explanations are probably appropriate.
Version 2 of the Apache server was a substantial re-write of much of the Apache 1.x code, with a strong focus on further modularization and the development of a portability layer, the Apache Portable Runtime. The Apache 2.x core has several major enhancements over Apache 1.x. These include UNIX threading, better support for non-Unix platforms (such as Microsoft Windows), a new Apache API, and IPv6 support. The first alpha release of Apache 2 was in March 2000, with the first general availability release on April 6, 2002.
Version 2.2 introduced a more flexible authorization API. It also features improved cache modules and proxy modules.