Apache JSSI parses JHTML files, executes the servlets as specified by the
<SERVLET> tag and replaces those tags with the output of the executed
servlet. The <SERVLET> tag can be seen as the server side equivalent of
the <APPLET> tag.

Note that SSI files for java servlets are called JHTML files in the
apache context while SHTML files are usually for traditional SSI (like
<!--#ECHO -->). This is a bit confusing since in the Java Web Server
(SUN) context SHTML files are used for java servlet SSI files and
JHTML is used for page compiled pages. Java Apache SSI does not support
page compiling.