Apache 2

Apache is popular open-source Web server software currently used on a large number of Web sites throughout the Internet (a study conducted regularly by NetCraft indicated that 57% of available Web servers were using Apache in July of 2002). The software itself is available free in both source code form and pre-compiled binaries from the Apache Web site for most platforms, including Windows, UNIX, and Linux.

Some of the many features of the Apache Web server include HTTP 1.1 compliance, support for Server Side Includes and conditional logic (for example, the ability to create a single copy of a Web page component such as a header or footer and "include" it in each of the site's pages, or to dynamically alter a page's contents based on the site visitor's browser or platform), unlimited URL aliasing/redirects, and support for virtual hosting. Additionally, the Apache server's API architecture allows developers to create customized plug-in modules to accomplish specific server related tasks and/or integrate their own applications or functions directly into the process of serving Web pages to visitors. Multiple modules are provided by default with the Web server itself and supply such broad functions as authentication and access control, support for CGI scripts, and support for HTTP header extensions and header information manipulation; as well as more specialized tasks such as the automatic correction of common URL typos. Additional modules are available from 3rd party vendors and provide such functionality as direct programming interfaces to external development languages (allowing developers to utilize a programming language transparently from within a Web page, for example) or specific database or system specific application connectivity.

Key enhancements in version 2 included support for UNIX Threading allowing the server to run in a "hybrid" multithread/multiprocess mode on supporting systems; platform specific "multi-processing modules" and the Apache Portable Runtime providing better integration with individual operating systems by providing native integration with the system's API; support for the next Internet Protocol version (IPv6); and support for filtered I/O allowing individual modules to act on and manipulate the content provided from a separate module before the information is ultimately sent on to the Web site visitor.

Apache 2 is available now. Visit the Apache Software Foundation Web site for further details.