is generally recognized as the world's most popular Web server (HTTP
server). Originally designed for Unix environments, the Apache Web server has been ported to Windows and other network operating systems
. The name "Apache" derives from the word "patchy" that the Apache developers used to describe early versions of their software.
The Apache Web server provides a full range of Web server features, including CGI, SSL, and virtual domains. Apache also supports plug-in modules for extensibility. Apache is free software, distributed by the Apache Software Foundation that promotes various free and open source advanced Web technologies.