Comment # 12 on bug 1118557 from Stefan Br�ns

(Traditional) TeX uses its own (vector) fonts, which are used to generate:

- metrics (tfm, TeX Font Metrics)
- bitmap renderings at print/display resolution (*.pk)

For the generation of DVI files, only metrics are relevant - it contains font
names and glyph positions, but no information how to render these fonts. A dvi
converter (dvipng, dvitopdf, xdvi) uses the names and positions to create a
graphical representation.

Later TeX gained the capability to use the standard postscript fonts
(Helvetica, Courier, Times, ...). It still uses its own metrics in TFM format,
but for the rendering (display, printing) the Type1 vectors fonts are used. For
backwards compatibility, the Postscript fonts are also available in PK format.

xdvi uses either the PK or Type1 font to render *the document contents*. Thats
what you are seeing when starting xdvi with/out -notype1fonts.


xdvi also uses fonts to display menus and the like. These are *not* rendered
using TeX fonts, but a completely different mechanism, X11 Core fonts.