Frequently loaded packages: Differences between pdfLaTeX and XeLaTeX

Question

Until now, I have been compiling my LaTeX documents with pdfLaTeX. My standard document preamble includes the "usual suspects" for non-English speakers (inputenc, fontenc, babel) and a bunch of other packages. Assuming I were to convert to XeLaTeX, what modifications of my preamble are advisable? I'm aware that the expansion=true option of the microtype package is not (yet) available for XeLaTeX, and that fontspec is sort of a default package for OpenType fonts. What other packages (and package options) should be removed and, vice versa, incorporated when switching from pdfLaTeX to XeLaTeX?

Answer 1

• Don't load inputenc or fontenc manually; use UTF-8 input and the fontspec package instead
• Don't load the textcomp package; if you want macros to enter varios symbols, load the xunicode package (EDIT BY LOCKSTEP: According to Ulrike Fischer, "[i]n a current system you don't need to load xunicode at all, fontspec will do it at the correct place")
• Use polyglossia instead of babel
• For OpenType math support, use unicode-math instead of amsfonts/amssymb etc. (but amsmath can/should still be used).
• The xltxtra package isn't necessary any more

Everything in this list is probably valid for LuaLaTeX, too, with the exception of xunicode and polyglossia, which require XeTeX.

Answer 2

Apart from the packages you mentioned, the only difference that I have is that I don’t load the inputenc package and don’t set a font encoding.

Furthermore, you should remove any explicit driver names if you have given them in options to packages (e.g. hyperref or xcolor). These driver names are wrong at worst and redundant at best, since the packages do find the correct driver automatically when loaded within xelatex.

Answer 3

Trying to implement all the answers and comments given in this thread using the ifxetex package, I ended up with the following code for my preamble. It allows to switch forth and back anytime between pdflatex and xelatex as compiler. Note: When switching the compiler, one should delete the aux files.

\documentclass[
    a4paper,
    ngerman
]{scrbook}

\usepackage{amsmath}

\usepackage{ifxetex}
\ifxetex
    % XeLaTeX
    \usepackage{polyglossia}
    \usepackage{fontspec}
    \usepackage[]{unicode-math}
    \setmainfont{XITS}
    \setmathfont{XITS Math}
\else
    % default: pdfLaTeX
    \usepackage{babel}
    \usepackage[T1]{fontenc}
    %\usepackage{lmodern}
    \usepackage[adobe-utopia]{mathdesign}
    \usepackage[utf8]{inputenc}
    \usepackage[babel=true]{microtype}
\fi

% some more packages like csquotes, biblatex, hyperref

\begin{document}
...
\end{document}

I had to load the amsmath package before the xelatex setmathfont command to avoid the error \dddot already defined. With MiKTeX 2.9 one has to manually install the XITS fonts using the MiKTeX package manager.