OpenType

A font format developed by Microsoft and Adobe that supports advanced typographic features including glyph substitution (GSUB) and glyph positioning (GPOS). OpenType fonts are critical for correctly rendering complex scripts such as Indian languages, Arabic, and Thai, where the visual form of a character depends on its context — adjacent characters may combine, ligate, or reposition. For accessibility, OpenType's ability to encode these contextual transformations within the font itself (processed by text layout engines like Uniscribe) means that assistive technologies can work with the operating system's rendering pipeline to correctly display and process complex script text.