All of our Unicode products (i.e., every OS X language kit provided by XenoType Technologies) requires a compatible Unicode font. On a Macintosh, Unicode fonts provide the most efficient way to provide the necessary information to an application about how to display a particular writing system.

Although Unicode fonts provide information about the features necessary to display a given script, which features to implement and the order used to implement them is left to the typeface developer. It is not sufficient (for many of the world’s writing systems) to simply provide Unicode codepoints in a font and expect the operating system to handle the rest.

We are one of the few companies that provides the necessary intelligence to display complex Unicode scripts and this is what makes our fonts unique. For example, our Tibetan font provides the information necessary to display a Tibetan ligature stack properly while virtually every other Unicode Tibetan font can only display the components of the stack, not the resulting ligature.

This situation is the main source of confusion for some users — installation of our kits does not enable a writing system universally across OS X, rather only when our font is used (in a compatible application). Moreover, OS X 10.2 currently processes Unicode character requests sequentially down the list of installed fonts in your system, looking for a font with the requested Unicode codepoint. It is entirely possible that you have a third party font which does in fact contain the necessary glyph but which does not provide the intelligence to display it properly.

In our Tibetan example, if you’ve installed Chinese, the font ST Heiti also provides access to Unicode Tibetan glyphs, but as you’ll note, it cannot display Tibetan properly. If you’ve installed our kit and find that Tibetan is not displaying properly, you should first check to see that our font is selected (most of our base fonts begin with XenoType and so they will typically appear towards the end of your font list).