SSI, Server Side Includes, are similar to RXML tags and have the advantage of being a standard supported by many web servers. It is thus possible to write pages using SSI that are portable to other web servers.

The downside is that SSI is in no way as flexible or powerful as RXML. The tags are placed within HTML comments, which makes it impossible to combine different SSI tags. However, it is possible to combine SSI tags with regular RXML tags.

Challenger does not presently implement all the SSI functionality that Apache supports.

The SSI tags are:

<!--#config-->

used to configure how things should be printed.

<--#echo-->

Prints a variable from the server or request.

<--#exec-->

Executes a CGI script or shell command.

<--#flastmod-->

Prints the last modification date of the specified file.

<--#fsize-->

Prints the size of the specified file.

<--#include-->

Insert a text from another file into the page.