.otf File — OpenType Font

OpenType is an advanced font format developed jointly by Microsoft and Adobe, extending the TrueType specification with additional typographic capabilities. OTF files can contain either TrueType outlines (quadratic Bézier curves) or PostScript CFF/CFF2 outlines (cubic Bézier curves), with the latter being preferred by professional type designers for their mathematical efficiency and smoother curves. OpenType supports advanced typographic features through GSUB (glyph substitution) and GPOS (glyph positioning) tables, enabling ligatures, contextual alternates, swashes, stylistic sets, small caps, old-style figures, and complex script shaping for Arabic, Devanagari, and other writing systems. The format can contain up to 65,536 glyphs, supporting extensive Unicode coverage and multiple scripts in a single font file. OpenType Layout features are accessed through CSS (font-feature-settings) or application typography panels. OpenType Variable Fonts (introduced in 2016) allow a single font file to contain an entire design space with continuous axes for weight, width, italic, optical size, and custom parameters. OpenType is the current industry standard for professional font development and distribution.