Hi Khaled,
OK, this is an odd one. Here's my test document:
\documentclass{book}
\usepackage{fontspec}
\setromanfont{Gentium:Ligatures=TeX}
This not the correct syntax; Ligatures=TeX is a fontspec option and
should be passed to it: \setmainfont[Ligatures=TeX]{Gentium}.
I also think that the correct syntax is
\setromanfont[Ligatures=TeX]{Gentium Book Basic}.
However,
\setromanfont{Gentium Book Basic:Ligatures=TeX}
also works here and Ligature=TeX seems to be effective.
Best,
Akira
--------------------------------------------------
Subscriptions, Archive, and List information, etc.:
http://tug.org/mailman/listinfo/xetex
