Text related packages advised to avoid combining

Question

In a recent question, a comment was left by @cfr in response to a line I included, specifically:

\usepackage{microtype,textcomp,textgreek,mathspec}

You should not be loading that mix of packages. If you are using Lua/XeTeX, then you should not be using textgreek or textcomp. If you are using (pdf)TeX, then you should not try to load mathspec

I use XeLaTeX and htlatex in sequential builds so my custom cls file is common and filled with if statements to recognize incompatibilities between the two compilers.

So, I wanted to post a separate question to get advice on these packages, specifically:

• textgreek: This package has been very important to be being able to include non math-mode greek characters in actual words while retaining the possibility to still use them in mathmode.
• textcomp: used to include objects such as registered trademarks and copyright symbols and fix htlatex html work
• mathspec : Specify arbitrary fonts for mathematics in XeTEX - must be loaded before fontspec
• microtype: I could be misremembering this one, but I think I needed it to solve a greek mu or gamma problem I had with siunitx or textgreek

I appreciate any insight to possible conflicts, alternatives, etc.

Answer 1

• microtype is fine. You will get slightly different results with different engines is all, depending on how well supported the engine is by the package or the package by the engine. (Everything works in pdfTeX. Xe/LuaTeX have differing levels of functionality.)

• mathspec should not be loaded when you are compiling with (pdf)TeX. You must be getting compilation errors if you are doing this.

  Never ignore compilation errors!

• textgreek uses a traditional font set-up. Use polyglossia etc. when compiling with Xe/LuaTeX. This will provide better support for Greek anyway. fontspec provides basic support, but polyglossia is much more powerful.

• textcomp use only with (pdf)TeX. It is not needed with Xe/LuaTeX.

[Filler text to format code]

\documentclass{article}
\usepackage{fontspec}
\begin{document}
  \textregistered{} \copyright
\end{document}