Mathematica versions 7 and 8 and specifically on linux, have issues with the greek letter rendering. This is an article describing a workaround for the issue.

The rendering problem is that mathematica handles greek letters even in text strings differently from other characters, because greek letters are important for mathematics. So when you use greek characters in strings on linux, in Graphics or Graphics3D objects the font used is not the custom one you specify. The result is a really awful rendering of greek fonts.

A workaround is to use custom modified unicode mapping files for mathematica kernel :

  • Let's say your installation of mathematica on linux is in /usr/local.
  • Go to the directory /usr/local/Wolfram/Mathematica/<Version number>/SystemFiles/FrontEnd/TextResources/. The <Version number> is 8.0 and 7.0 for your specific version of mathematica.
  • The file to be customized is UnicodeFontMapping.tr. Make a backup of the file.
  • Replace the file UnicodeFontMapping.tr with the downloaded file.
  • - Done!

Now the font use in mathematica for greek texts and all the Style settings work fine as you can see on the picture below:

 

Mathematica unicode greek rendering