[XeTeX] The future of XeTeX

Adam Twardoch (List) list.adam at twardoch.com
Tue Jul 31 12:01:08 CEST 2012

On 12-07-31 11:34, Jonathan Kew wrote:
> ...of misinformation, I'm afraid.

Keith J. Schultz <keithjschultz at web.de> wrote:
>> Let us take ATSUI. Why has Apple abandon it? Well, I do not believe
>> there are are any native ATT-fonts in the MacOS X any more.
Most complex-script fonts (Arabic, Indic etc.) that ship with Mac OS X
are AAT, and continue to be. In fact, Apple is actively developing AAT:
Mac OS X 10.8 Mountain Lion has support for a new "kerx" table which
allows for horizontal and vertical class-based kerning, much akin to the
OpenType Layout GPOS table. AAT is also actively supported on iOS,
especially for performance issues (the layout of AAT complex-script
fonts is approx. 3x faster than of OTL fonts with comparable
>> Is Core Text a alternative? Not, actually.
> Yes, actually. Core Text is the modern, supported replacement for
> ATSUI functionality.
AAT is Apple's layout technology. ATSUI and CoreText are different APIs.
Similarly, OpenType Layout is another technology. Analogically, HarfBuzz
and Pango are two different APIs for that.
> Core Text doesn't have "support for ATSUI" in the sense of providing a
> set of ATSUI-clone APIs to applications, but it most certainly does
> have support for AAT fonts, which is the relevant issue here.
True. One aspect of AAT that CoreText may have dropped (but ATSUI still
has) is TrueType variations (fvar/gvar table) -- though I'm not entirely
certain of it. But, as mentioned above, AAT is being actively developed,
contrary to what you may believe.



May success attend your efforts,
-- Adam Twardoch
(Remove "list." from e-mail address to contact me directly.)

More information about the XeTeX mailing list