Jonathan Fine
But DVI lacks an essential feature of TeX, which is the TeX macro language. I count this as a benefit of DVI, not a deficiency. Standards restrict, and by restricting enable.
This may be a case of 'If you build it, they will come': present a set of tools making XDVI useful, and then maybe people will want to write code for it. Having written the clumsy XDVI support for ant (ant.berlios.de) a few years ago, and somewhat less clumsy support for unpublished software, I am trying to recall in what important ways XDVI differs from regular DVI. I _think_ (my memory may be wrong) the deal was that to use a non-tfm font you had to use the new glyph-writing opcodes. Otherwise it's almost exactly like using dvipdfm. I don't know what XeTeX does but in both the cases mentioned above I use glyph-index encoding. To make that portable you would have to include in the xdv file a map from glyph indexes to Unicode strings, perhaps using specials.