There are various ways to use Tcl in ADPs like ASP or JSP.
You can use the <% ... %> and <%=
... %> tags just as in an ADP page handled by the
AOLserver. For examples, see the section "embedded tcl" on the
demonstration page.
Generally, avoid putting escaped Tcl code in adp files, or generating HTML fragments in tcl procedures. It subverts the separation of code and layout, one of the benefits of templating. Embedded Tcl makes templates non-portable to ACS/Java.