Typotheque webfonts support all languages supported by their print versions. That’s over 200 languages, including those using Cyrillic, Greek and Arabic scripts.
Latin, Greek, Armenian and Cyrillic scripts render consistently in all browsers, but complex scripts such as Arabic or Devanagari require AAT fonts for correct shaping on Macintosh. That means that Windows renders the fonts correctly, but Mac renders in the fallback font (rather than showing unshaped glyphs). We hope that Apple will extend their support for OTF and TTF fonts to render complex scripts correctly.