LuaTeX vs XeTeX

[Herbert Voss]

Am 16.12.21 um 21:02 schrieb Virgil Arrington via lyx-users:
>
> On 12/16/2021 9:31 AM, Herbert Voss via lyx-users wrote:
>
>
>     LuaTeX ,and XeTeX too, are more or less frozen code, just like TeX.
>     Only bugs will be fixed. There are no good reasons _not_ to use
>     LuaTeX instead
>     of pdfTeX:
>
> I just performed an interesting experiment comparing the results from 
> compiling the same source file with XeTeX, PDFLaTeX and LuaTeX. I was 
> surprised by the results I got. In the past, I had found that, when I 
> used XeTeX, I got more "overfull hboxes" with lines flowing past the 
> right margin than I did with PDFLaTeX. I also would get *many* more 
> hyphenated words with XeTeX than with PDFLaTeX. I assumed I would get 
> similar results with LuaTeX, but I was pleasantly surprised.
>
> For my experiment, took a 45 page paper I wrote for a former employer. 
> For the PDFLaTeX compiled version, I used the mathpazo Palatino font 
> that came with MikTeX and compiled it with PDFLaTeX. For the XeTeX and 
> LuaTeX versions, I used Windows' Palatino Linotype font. All other 
> settings were the same, including the use of the Microtype package in 
> all versions.
>

Other font, new kernings, new hyphenations.
mathpazo (Type 1) and Palatino (TrueType) are not the same font!

> In a single random paragraph, the resulting file compiled with XeTeX 
> gave me eight hyphenated line endings. The same paragraph in the 
> document compiled with LuaTeX gave me three hyphenated line endings, 
> and the same paragraph in the document compiled with PDFLaTeX only 
> gave me one hyphenated line ending.
>
> XeTeX also gave me many overfull lines, in fact so many as to make the 
> resulting document all but unusable. PDFLaTeX gave me a few, but I 
> could work with them. I was surprised to see that LuaTeX appeared to 
> give me the fewest overfull lines. I saw very few lines that extended 
> beyond the right margin, and those I did happen to find extended such 
> a small amount as to be all but unnoticeable.
>
> I was very surprised by how different the results were when using 
> XeTeX vs. LuaTeX. I had just assumed that the two engines would 
> produce very similar results, but that was not the case at all. In 
> fact, having seen LuaTeX's document, I can't imagine why anyone would 
> choose XeTeX over LuaTeX. I was also surprised to see how well 
> LuaTeX's results compared with PDFLaTeX's document. While LuaTex still 
> gave me more hyphenated line endings, it gave me fewer noticeable 
> overfull lines at the right margin.
>

Do _not_ load any font and choose an empty preanble,
  then Computer Modern is used for pdflatex and Latin Modern
for lualatex/xelatex. And then you will see _no_ difference in
the created pdf.


Herbert