Here's the problem, simply put: OpenType fonts use a different structure to provide access to font features (e.g., small caps, swashes, true fractions, etc.) than Macintosh TrueType fonts. Apple, most likely under pressure from Microsoft and Adobe (the creators of the OpenType font format), has decided that it would be helpful if people could access these and other features in OpenType fonts on a Macintosh. As a result, Tiger now looks for the presence of OpenType font features and converts them to Apple's own format. The problem with this approach is that it then ignores the existence of its own native format for font features. You'd think this wouldn't be a big deal, but OpenType, regardless of the hype, does not provide a sufficient featureset to display many of the world's writing systems. It requires the presence of an adjunct file which [currently] only exists under Windows.

Why all of this is bad...bad...bad: A cross-platform font that contains OpenType features as well as native AAT features no longer works as intended because the intelligence in the AAT tables is ignored by Tiger. Crippling Apple's superior ability to handle writing systems seems like a high price to pay for what amounts to typographic niceties (no offense to people who use and enjoy swashes and old style numerals). Even scarier is the thought that Apple might be abandoning its technology altogether in favor of something obtrusive (no doubt to be licensed from Microsoft).

Under the OpenType model, Microsoft must 'bless' a writing system before it will work and that means if Microsoft thinks your writing system is insignificant or otherwise unworthy of their development time, your favorite script isn't going to work. Under Apple's structure, developers decide if, when and how they support a writing system — no waiting for rich corporati to decide when a script is marketable.

Harsh words? Maybe. But for small developers like us (they're aren't many of us, admittedly), this will be impossible to deal with. Take Tibetan or Burmese for example, these have been possible for years on a Macintosh, but still have yet to be officially adopted by Microsoft. Even the upcoming release of Longhorn is unlikely to support Burmese. Do you really want to wait for Microsoft to decide when you can type in your native script?