Arno Trautmann a écrit : > It will not be used anymore if there is a more comfortable, maybe > faster, and at all ”better“ engine. LuaTeX seems to be this (not faster, > but the rest …) so I am using LuaTeX already for production of (small) > documents. It’s annoying however that I have to load packages to use it > (fontspec etc.) – it would be great to have this implemented in the > kernel which is only possible by fully setting on luaTeX. > I disagree on one point: fully setting on LuaTeX is not the only way. One could imagine an architecture like that: - the very core of the kernel using only features common to pdfTeX, XeTeX and LuaTeX (perhaps with some emulation, such as implementing pdfstrcmp in Lua). Mostly as it is now, I believe, but replacing e-TeX with the least common denominator of the 3 modern engine: I don't see the point in sticking to e-TeX). - then a more modular part of the kernel, according to the engine being used. Here, something like fontspec could be included. It would work in "restricted" mode with pdfTeX (maybe similar to LaTeX2e+inputenc+fontenc, except that I don't see any need to hack stuff for utf-8 input) and in "standard mode" with any of XeTeX and LuaTeX, and in "enhanced mode" with LuaTeX (eg additional microtypography à la pdfTeX). From the user point of view, no need to load any package, everything is in the kernel. Then if you say "latex3 --pdftex" you have a certain set of features available, but perhaps a better level of portability, and "latex3 --xetex" or "latex3 --luatex" gives you access to another features/portability tradeoff. Disclaimer: I'm not saying this is what should be done. As a matter of fact, I do not (yet ?) have a clear opinion about how latex3 should handle the engine question. I'm just saying this is an option that may be worth considering. (I also think that "native" (whatever it means) support for modern engines would be a big plus in the adoption of latex3 as a successor to the well-established latex2e.) >> In practical terms there will be some sort of latex3[.exe] program >> provided by TeX distributions to compile documents in LaTeX3 format. >> It might as well point to LuaTeX engine and no one will know any >> better. > I'd like to hear good arguments for not doing so. Is there any reason to think that LuaTeX will not be as good as XeTeX at some point? Any fear it doesn't become stable before LaTeX3 is? Manuel.