Reading direction can be right to left, left to right, or vertical. Some scripts depend on specific contextual forms for each glyph, while others rearrange glyphs depending on the context. Many of the features of TrueEdit are designed expressly to support these effects. Some features are not new ideas with GX, but GX greatly expands on previous font capabilities. Vertically written GX fonts can contain vertical metrics information, equivalent to the horizontal metrics information used for scripts such as Roman.
Embedded bitmaps can relieve the difficulty of creating instructions for very complex glyph designs.
New script features in GX include baselines , which govern the alignment of adjacent text in different scripts, and glyph properties , which Line Layout uses to resolve cases where two or more scripts run in different directions on a single line. So that a font may be used anywhere in the world on a GX system, localized names can be provided in any script or language available on the Macintosh. These script and language features combine with glyph and position effects to support virtually any writing system. Which features are relevant to a particular font depends on the script or scripts it represents. For vertical scripts such as Mongolian, vertical metrics are essential.