[XeTeX] Eplain, ifpdf.sty, XeTeX and ifxetex.sty

[Bruno Voisin]

Another of my stir-the-pot messages of this morning:

At times I consider using Eplain temporarily for a change <http:// 
www.tug.org/eplain/>, to still have access to cross-referencing  
facilities and the like, and at the same time to have easier control  
of the formatting of a document without needing to load additional  
packages or to write tens of lines of redefinitions of "@-style"  
LaTeX control sequences in the preamble of the document.

As it happens, Eplain is now at version 3 which includes -- big  
change -- hyperlinking facilities akin to those offered by the  
hyperref package under LaTeX. Alas, the version in teTeX and hence  
provided in the TeX i-Package is version 2. The installation of  
Eplain v3 seems to involve Makefile's -- if only to compile the  
documentation -- which for a non-developer (like me) is a show- 
stopper. And Gerben is currently on holiday near the Pyrenees, which  
makes the creation of an Eplain updater i-Package (should Gerben  
think it appropriate) something currently impossible.

Back to topic, and to the original motivation for this message: the  
hyperlinking support in Eplain has been designed for the drivers  
dvips, pdfTeX and dvipdfm. Given the specials in XeTeX use the same  
syntax as dvipdfmx, I imagine that should make this support available  
to XeTeX as well. A check for PDF output is provided through the  
ifpdf.sty package, based on \pdfoutput <http://www.tug.org/eplain/doc/ 
eplain/Checking-for-PDF-output.html>. Two thoughts:

- Would this mechanism correctly detect PDF output for XeTeX?

- This shows the pertinence of Will Robertson's package ifxetex.sty,  
providing a reliable check for XeTeX through a stand-alone package,  
as ifpdf.sty does for pdfTeX.

No hurry for anything here, I just thought interesting to share a few  
thoughts that arose this morning when browsing TUG's site and  
realizing a major update to Eplain had taken place a few months back.

Bruno Voisin