Most of the Graphics demos distributed uses the following fonts:

Gentium:
http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&cat_id=FontDownloads

FireFlySung:
http://www.unifont.org/fontguide/

UnBatang:
http://www.unifont.org/fontguide/

VeraMono:
http://www-old.gnome.org/fonts/#Final_Bitstream_Vera_Fonts

Jaipur:
http://ccat.sas.upenn.edu/plc/hindi/jaipur/jaipur.zip

DB ThaiText:
http://www.thai-language.com/downloads/dbtt.ttf

The license for these mentioned fonts are available in one of their their parent webpages