CGI - Common Gateway Interface
The Common Gateway Interface (CGI) is a standard for interfacing external applications with information servers, such as the Apache Web Server. An HTML document is static, which means it exists in a constant state. It is a text file that doesn't change. A CGI program, on the other hand, is executed in real-time so that it can provide dynamic output.

• CGI Library

Installation
Your Virtual Private Server features full CGI support.

• Installing and Debugging Your Own CGIs
• CGI Security Issues

Configuration
CGI programs that are installed in the ~/www/cgi-bin directory will automatically be executed by the Web server when accessed from a Web browser. If you install CGI programs in the ~/www/htdocs directory, they will not be automatically executed by the Web server. To configure the Web server, connect to your Virtual Private Server via Telnet or SSH and do the following.

1. Uncomment this AddHandler directive in the Web server configuration file (~/www/conf/httpd.conf):

   AddHandler cgi-script .cgi

   You may want to add a Handler for Perl scripts:

   AddHandler cgi-script .pl

2. Add an ExecCGI option to the Options for your Root Document declaration (<Directory /usr/local/etc/httpd/htdocs>) also in the Web server configuration file (~/www/conf/httpd.conf):

   Options Indexes FollowSymLinks ExecCGI

3. Restart Your Web Server