Apache HTTP Server 2.4.2 / 2.2.22 / 2.0.64 / 1.3.42

This is a collaborative software development effort aimed at creating a robust, featureful, commercial-grade and freely-available source code implementation of an HTTP (Web) server.

Here are some key features of "Apache HTTP Server":

· Authn/Authz - The bundled authentication and authorization modules have been refactored. The new mod_authn_alias module can greatly simplify certain authentication configurations. See module name changes, and the developer changes for more information about how these changes affects users and module writers.
· Caching - mod_cache, mod_disk_cache, and mod_mem_cache have undergone a lot of changes, and are now considered production-quality. htcacheclean has been introduced to clean up mod_disk_cache setups.
· Configuration - The default configuration layout has been simplified and modularised. Configuration snippets which can be used to enable commonly-used features are now bundled with Apache, and can be easily added to the main server config.
· Graceful stop - The prefork, worker and event MPMs now allow httpd to be shutdown gracefully via the graceful-stop signal. The GracefulShutdownTimeout directive has been added to specify an optional timeout, after which httpd will terminate regardless of the status of any requests being served.
· Proxying - The new mod_proxy_balancer module provides load balancing services for mod_proxy. The new mod_proxy_ajp module adds support for the Apache JServ Protocol version 1.3 used by Apache Tomcat.
· Regular Expression Library Updated - Version 5.0 of the Perl Compatible Regular Expression Library (PCRE) is now included. httpd can be configured to use a system installation of PCRE by passing the --with-pcre flag to configure.

What's New in This Release: [ read full changelog ]

· This release requires the Apache Portable Runtime (APR) version 1.4.x and APR-Util version 1.4.x. The APR libraries must be upgraded for all features of httpd to operate correctly.
· This release builds on and extends the Apache 2.2 API. Modules written for Apache 2.2 will need to be recompiled in order to run with Apache 2.4, and require minimal or no source code changes.