The document area is where the current  document  is  shown.
The  formatting  used  is  determined by the document's MIME
type, as indicated by the Content - type  HTTP  header.   We
currently recognize the following MIME types:

text/html
   HTML 3.2 is the standard that we have used.   This  is  a
   highly-experimental  program,  of  course; which parts of
   the standard are implemented (and how) changes rapidly.

text/plain
   All unrecognized MIME types are displayed as plain  text,
   which  means  that  the data is simply loaded into the tk
   text widget unexamined, and displayed however  the  local
   tk  package is configured.  Typically this means that the
   ISO 8849-1 (Latin-1) encoding scheme is used.

Within an HTML document, we show the text in several colors,
depending  on  the nature of the text.  We recomment using a
neutral gray (gray50) color for the background and a  bright
foreground color, but this is up to you. Here are the colors
that we currently use:

X*foreground
   ordinary text.
cyan
   hyperlinks.
orange
   named anchors.

See also the uses of the C() array in the code.