Re: ConTeXt, XeTeX, ect was Re: OpenType in Windows

["luigi scarso" <luigi.scarso@gmail.com>]

On 4/5/07, Sanjoy Mahajan <sanjoy@mrao.cam.ac.uk> wrote:
> > What does this exactly mean (from wikipedia)?
> > "XeTeX works well with both LaTeX and ConTeXt."
>
> XeTeX, PDFTeX, eTeX, and TeX (Knuth's original TeX) are conceptually
> at the same level.  The ConTeXt documents (and kpathsea) call this
> level the engine.  They all understand basically the same macro
> language, the one Knuth described in the _TeXBook_.
>
> But they have slight differences.  For example, TeX produces DVI
> output.  eTeX does too but it adds a few more commands ('primitives')
> to the macro language.  PDFTeX produces PDF directly (or can produce
> DVI) and has, relative to regular TeX, new macro commands to support
> features of PDF; for example, \pdfpagewidth is new to PDFTeX.  Regular
> TeX doesn't have an equivalent because the DVI format does not include
> a notion of page size.  PDFTeX, from v1.40, also incorporates those
> eTeX commands.  And XeTeX has commands to support OpenType, which is
> the new standard font format.
>
> LaTeX and ConTeXt are large programs ('macro packages') written on top
> of the engine.  Namely, the program -- whether LaTeX or ConTeXt -- is
> written in the macro language of the engine.  Most of the program is
> independent of the engine, but there are a few changes needed; the
> program usually detects which engine is being used underneath it and
> adjusts what it does accordingly.
>
> For LaTeX, you choose the engine by the name of the program you run:
>
> * latex    -- uses regular TeX (actually, now it uses PDFTeX pretending
>   to be regular TeX)
> * pdflatex -- uses PDFTeX
> * xelatex  -- uses XeTeX
>
> For ConTeXt, you choose the engine by the '--engine' option to
> texexec.  For example: "texexec --engine=pdftex file.tex" will make
> you file.pdf.  But as the manual entry now says, you usually do not
> need to specify the engine:
>
>        --engine=texengine
>               Specify the program to do the hard work of typesetting.
>               Currently either pdftex (the default), xetex, or aleph.
>               The luatex value is experimental.  The --engine option
>               is not usually needed.  Instead, let texexec figure out
>               the setting based on other command-line information.
>               See for example the --xetex or --pdf switches.
>
> So
> * "texexec --xetex file.tex" : uses XeTeX
> * "texexec --pdf file.tex"   : uses PDFTeX
> * "texexec file.tex"         : also uses PDFTeX (the --pdf option is
>                                now the default to texexec)
>
> I hope this explanation clarifies.  If so, you can Wikify (on
> wikipedia and/or the ConTeXt wiki)!
>
> -Sanjoy
About  luatex: see it as a new entry in the list
XeTeX, PDFTeX, eTeX, and TeX
ie
luatex ,XeTeX, PDFTeX, eTeX, and TeX

luatex add a script language (lua) to tex .

Note that
PDFTeX> eTeX> TeX
(where 'A>B' means A include B)
and that
luatex > PDFTeX U Aleph.
There is a bit of confusion about luatex:
someone says "luatex will be pdftex2.0",
someother says "pdftex will be frozen to 1.5 and there will be luatex".
Given that I played with luatex, I prefer the second, or even
"luatex will be pdftex4.0"

luigi

luigi