SUMMARY:  A Unicode typesetting system based on TeX

DETAILS:  XeTeX is a typesetting system based on a merger of Donald Knuth's TeX system with Unicode and modern font technologies and is still in the experimental stage of its development.

XeTeX is a command-line tool, like standard TeX and pdfTeX processors. It is most commonly used via a graphical environment such as TeXShop (Mac OS X), KILE (Linux), WinEDT (Windows), or others.