[XeTeX] XeTeX and luaTeX

[Will Robertson]

On 2010-06-05 18:42:06 +0930, Pablo Rodríguez 
<oinos at web.de> said:

> Which will be those differences between podTeX and LuaTeX?

I can't remember where it's talked about, but I think the relevant 
details are that there are minor incompatibilities in kerning and 
hyphenation and justification when typesetting paragraphs. Basically, 
on any arbitrarily large pdfTeX document, you can't guarantee you'll 
get the same output when typeset with LuaTeX. (As a change in 
hyphenation can change a single line break, which can change a page 
break, which can change a chapter break...)

Of course, there's also some differences in extended funtionality, such 
as the pdfTeX primitives that are only available with Lua in LuaTeX, 
but Heiko Oberdiek's pdftexcmds provides a unified interface to this 
(and to the relevant XeTeX primitives as well).

Certainly nothing to worry about (especially because hyphenation 
patterns aren't as constant in the TeX world as TeX itelf), but 
necessary to be aware of.

Cheers,
Will