Re: [NTG-context] Difference between MKII, XeTeX and MKIV

On Mon, Mar 14, 2011 at 19:44, Marco wrote:
> On 2011-03-14 Cecil Westerhof wrote:
>> 2011/3/14 Marco wrote:
>> > On 2011-03-14 Cecil Westerhof wrote:
>> >
>> > > When installing minimals you have MKII, XeTeX and MKIV. I understand
>> > > that you should normally use MKIV, but when are the other two used?

They are mostly relicts of the past which still happen to be
supported. (But if ConTeXt was written from scratch, there would
probably be no support for them.)


I often write mathematical-oriented papers that need zero tweaking
with OpenType fonts, complex layouts or that could benefit from lua
scripting. I compile those randomly with MKII and MKIV, if nothing
else to check for differences, or if there is a problem in MKIV, I can
always use MKII is a fallback. MKII hardly ever changes, so it is
slightly more reliable in some cases, but it is very limited in
comparison to MKIV.

I use XeTeX mostly when I need OpenType fonts and something in MKIV
breaks. XeTeX has some advantages in out-of-the-box support for exotic
scripts (which I don't use), but many of its features are not
supported in ConTeXt at the high-level user interface. In general,
XeTeX is the least supported engine in ConTeXt community. In contrary,
for LaTeX users XeTeX is becoming the mainstream engine to use (best
supported by active developers).

>> > MKII can be used either with pdftex or xetex (as you wish, compare
>> > advantages/disadvantages). MKIV can only be used with luatex.
>> >
>> > You have to differ between ConTeXt »versions« (mkii, mkiv) and TeX
>> > backends (pdftex, xetex, luatex).
>> >
>>
>> And where do I find the advantages/disadvantages?
>
> Wikipedia, google, information source of your slightest distrust.
> Short and incomplete:
>
> pdftex:
> + protrusion, font expansion
> - fonts are a nightmare
(you should have put three minuses there :)
+ stability

> xetex:
> + system fonts are easily accessible
> - no protrusion, no font expansion

I never tried to use them, but I thought that Han The Thanh [please
add the accents] added that to XeTeX semi-recently
(http://scripts.sil.org/svn-view/xetex/TRUNK/, the last comment 8
months ago: "merged microtype branch to trunk").

> luatex:
> + protrusion, font expansion, easy access of system fonts, scripting language
>  included, fast with mplib
> - in general much slower

... depending on whether "in general" includes metapost or not. A
speed factor of ten (faster) is nothing unusual for luatex when many
metapost graphics come into play.

++ better support

>> Or can I just always use MKIV?
>
> Yes, you can.

Definitely. You don't need to bother, just stick to MKIV as long as it
works fine for you.

Mojca