The second component of the web-service solution stack is the Apache HTTP web server. Apache is a free and open source cross-platform web server and is currently the world's most commonly used web server software. Released in 1995, Apache was originally based on the NCSA HTTPd server, one of the earliest web servers, and was developed by Robert McCool. When development on the NCSA HTTPd code stalled, development on Apache began and it quickly established itself as the dominant HTTP server, remaining popular ever since. Over 54% of web servers currently run Apache. The Apache software and its documentation are developed and maintained by the Apache Software Foundation; a group of volunteers located across the world. Apache was the first web server software to serve more than 100 million websites and played a crucial role in the initial growth of the World Wide Web.
Apache can be configured to suit the needs of the user / application and is highly extensible.. Compiled modules extend the core functionality, ranging from server-side language support, such as PHP, Perl and Python, to authentication schemes such as mod_access and mod_digest. The server we are using for this couruse - dialogplus is currently running apache.