Apache HTTP Server
Apache HTTP Server (commonly called Apache) is a free and open-source cross-platform web server software developed and maintained by the Apache Software Foundation. It is one of the most widely used web servers on the Internet, serving a significant share of all active websites. Apache supports a modular architecture, allowing administrators to extend its functionality through modules for authentication, caching, HTTP compression, and more.
History
The Apache HTTP Server project began in 1995 as a community-driven improvement of the NCSA HTTPd server, which was the dominant server at the time. A group of volunteer developers patched and extended NCSA HTTPd, releasing the first public version (0.6.2) in April 1995. The name "Apache" was chosen in honor of the Native American Apache tribe, as well as a playful reference to the project's "a patchy" origins. Version 1.0 was released in December 1995, and the server quickly grew in popularity. In 1999, the Apache Software Foundation was formed to provide organizational support. Version 2.0, released in 2002, introduced major architectural changes including support for multithreading and improved POSIX compliance. The current stable series is 2.4, which continues to receive security updates and new features.
Features and architecture
Apache's core feature is its modular design. Key features include:
- Support for multiple virtual hosting (name-based and IP-based)
- HTTP/2 and HTTPS via OpenSSL or mod_tls
- Extensible authentication mechanisms (mod_auth_basic, mod_auth_digest, mod_authz_core)
- URL rewriting and redirection with mod_rewrite
- Server-side scripting through CGI, FastCGI, mod_perl, mod_php, and mod_proxy
- Caching proxies and reverse proxy capabilities (mod_proxy, mod_cache)
- Logging and monitoring with mod_log_config and mod_status
Apache uses a prefork or worker MPM (Multi-Processing Module) to handle incoming requests, balancing stability and performance. Configuration is typically done via plain-text directives in files such as httpd.conf or .htaccess. The server runs on Unix-like systems and Microsoft Windows.
Apache's popularity peaked in the early 2000s but remains widely used, especially in shared hosting environments and legacy deployments. It is often compared with Nginx and Microsoft IIS.