Apache is the worldwide most used Web server. The Apache project is managed by the Apache Software Foundation and it was originally based on NCSA HTTPd server; the development of Apache began in 1994 and the first release was in April 1995.

This Web server is available for several Operating Systems like Microsoft Windows, NetWare and OpenVMS, but the main use is on Unix-based systems, in particular on Linux distros. Actually it's estimated that Apache runs 50% of the active Internet Web sites.