The character-glyph model is a fundamental aspect of the Unicode standard and has a significant impact on how Unicode is to be implemented. This is particularly true for Middle Eastern and South Asian scripts, but it is also the case for relatively "simple" Unicode scripts such as Latin and Cyrillic.

Although initial implementations of Unicode tended to focus on scripts which can be displayed without use of the character-glyph model, more sophisticated implementations are coming into common use which provide full support for the character-glyph model.

We will examine a series of specific problems where Unicode support is impossible without the use of the character-glyph model or where support is greatly enhanced by using it. These problems will be drawn both from "simple" Unicode scripts (such as Latin, Greek, and Cyrillic) and from "complex" scripts (such as Arabic and Thai). Solutions to these problems will be illustrated using available technologies, with particular focus on TeX, OpenType, and Apple Advanced Typography.