Chapter 13. Server Side Includes

Server Side Includes (SSI) are directives you can place into an HTML document to execute other programs or to output data, such as file statistics or the contents of environment variables. SSI directives can save you the trouble of writing complete CGI programs to output documents containing a small amount of dynamic information. While Server Side Includes are not technically CGI, they can become an important tool for incorporating CGI-like information as well as output from CGI programs.

Keep in mind, however, that not all servers support these directives. In addition, some servers allows the setting of server-side variables, which can be used in Extended Server Side Includes (XSSI) conditional expressions. These expressions determine which portion of a server document should be displayed.