Just go to Glyphs, on the font presentation page.
Besides modern Greek, TPTQ Arabic Pro fonts also support Greek Polytonic, with the variety of diacritics used to write pre-reform and ancient Greek.
Briefly, OpenType is a font format jointly developed by Adobe and Microsoft in the late 1990ʼs. It came into wider use only after 2000, when Adobe included support for advanced typographic features in their InDesign, PhotoShop, and Illustrator applications.
We offer fonts primarily in OpenType format. OpenType is the only cross-platform format, i.e. the same file will work on both Macintosh and Windows computers.
While all OpenType fonts will work in nearly all existing software, only some applications take full advantage of OpenTypeʼs advanced layout features. Applications such as InDesign, Illustrator, PhotoShop, QuarkXPress 7 (and higher), Word 2010 and Mellel offer these options.