Q:

Cannot use xgreek in XeLatex with Fedora

I am trying to enable greek hyphenation in a XeLatex document.  But when I do I get:
|Package `xgreek' version 2.4 by Apostolos Syropoulos
|!  Undefined control sequence. 
|\ds@monogreek ->\language \l@monogreek
l.445 \ExecuteOptions{monogreek}
? 
|!  Emergency stop. 
|\ds@monogreek ->\language \l@monogreek
|l.445 \ExecuteOptions{monogreek}

Here is a snippet to reproduce it:
\documentclass{article}
\usepackage{xgreek}
\begin{document}
\end{document}

For what is worth I'm using Fedora and my XeTex version is 3.1415926-2.5-0.9999.3 (TeX Live 2013).  If I recall correctly I didn't have issues with other Linux distributions, so this may be a distribution-specific issue ? 

A:

The code-snippet is empty.  Package 'xgreek' is not necessary to write greek (polytonic or
monotonic).  Working with Xe(La)Tex the following MWE perhaps will help:
\documentclass{article}
\usepackage{xgreek}
\usepackage{fontspec}
\setromanfont{Minion Pro} %% Select your favourite font
\usepackage{polyglossia}
\setmainlanguage{greek}
\setotherlanguage{english}
\begin{document}

This is english. 

Γιατί δεν λειτοργεί;
\end{document}

