To send a block to a process, and include it's output in the source *in
compile time*, use the preprocessing tag.
For example, to use the output of a Python script:
<HTML>
<@python>
for x in range(0, 10):
    print x + "\n"
</@>
You should see numbers 1 to 10.

This will be generated in compile time, not in run time.

To include TCL code in your application:

<HTML>
<#
   $perl_var++;
>
<? puts $per_var ?>

This uses the Tcl module which you must install.
perl scalars and arrays can be accessed from Tcl.
