Microsoft and Apple developed OpenType format [OpenType]. This format has various tables and is more expressive than Type1 and TrueType [TrueType], but less expressive than AAT. Applications rely on a platform library to render text well for a complex writing system (like ours) - or do it themselves. On Windows, Uniscribe [Uniscribe] is such a library. We need to find out, how well it really supports, as they said, "the use of kerning for adding space to bases with diacritics (Nikud or Teamin)". On Linux, this is done by Pango [Pango], and it, it seems, does not deal with cantillation at all - just with consonants and vowels [PangoH]; we need to contact them, find out what the situation is and possibly change it. Firefox (the only program that we care about) uses Pango, which works on Windows (via Uniscribe), and on macOS.