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) and Mellel offer an interface for controlling these options.
Older applications such as QuarkXPress 6, FreeHand only offer access to the first 256 glyphs of the fonts, ignoring the others. Fedra Sans Pro, for example, includes over 2,500 glyphs, so in these programs you will be only able to use about 10% of the fontʼs possibilities.
It is preferable to use PostScript fonts in such older applications.
Unicode-compliant applications such as Word will be able to access all glyphs with Unicode values, but not stylistic variants (numerals, small caps, ligatures, etc).