Am 2016-04-06 um 03:51 schrieb Jan Tosovsky
<cite> Note that character protrusion requires pdfTeX (version 0.14f or later), LuaTeX, or XeTeX (at least version 0.9997). Font expansion works with pdfTeX (version 1.20 for automatic expansion) or LuaTeX. The package will by default enable protrusion and expansion if they can safely be assumed to work. Disabling ligatures requires pdfTeX (≥ 1.30) or LuaTeX,
************************************************ while the adjustment of interword spacing and of kerning only works with pdfTeX (≥ 1.40).
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Letterspacing is available with pdfTeX (≥ 1.40) or LuaTeX (≥ 0.62). </cite>
Looks like it’s not about interword spacing and kerning in itself, but their *adjustment*. I didn’t look into that docs, but I’d assume, tracking refers to some logging or visualization of spacing. AFAIR ConTeXt can do that very nicely (while I never used it and don’t know how to enable it). Greetlings, Hraban --- http://www.fiee.net http://wiki.contextgarden.net https://www.cacert.org (I'm an assurer)