Apache Archive
When Apache generates any web pages or error pages, some important information about the version and other details implemented on the system are displayed in th web site server header. For example, the information text may be like this:
Server: Apache/1.3.37 (Unix) mod_auth_passthrough/1.8 mod_log_bytes/1.2 mod_bwlimited/1.4 FrontPage/5.0.2.2635.SR1.2 mod_ssl/2.8.28 OpenSSL/0.9.7a PHP-CGI/0.1b
Server: Apache/2.0.53 (Ubuntu) PHP/4.3.10-10ubuntu4 [...]