The Source.tclindow shows the text as  received,  without  any
formatting.   It has two scrollbars, and a '*' button in the
corner that clears the window.

The Opts menu has an entry that  says  either  "Show  Source
Window"  or  "Hide Source Window"; these may be used to open
and close this window.  There is also a "Show Header Window"
entry in the Opts menu that will open up a window that shows
the HTTP header information for the URL.