fonts TrueType is a font system originally developed by Apple Inc. It was intended to replace Type 1 fonts, which many felt were too expensive. Unlike Type 1 fonts, TrueType glyphs are described with quadratic Bezier curves. It is currently very popular and implementations exist for all major operating systems. OpenType fonts OpenType is a smartfont system designed by Adobe and Microsoft. OpenType fonts contain outlines in either the TrueType or CFF format together with a wide range of metadata. Stroke-based fonts A glyph's outline is defined by the vertices of individual stroke paths, and the corresponding stroke profiles. The stroke paths are a kind of topological skeleton of the glyph. The advantages of stroke-based fonts over outline fonts include reducing number of vertices needed to define a glyph, allowing the same vertices to be used to generate a font with a different weight, glyph width, or serifs using different stroke rules, and the associated size savings. For a font developer, editing a glyph by stroke is easier and less prone to error than editing outlines. A stroke-based system also allows scaling glyphs in height or width without altering stroke thickness of the base glyphs. Stroke-based fonts are heavily marketed for East Asian markets for use on embedded devices, but the technology is not limited to ideograms. Commercial developers included Agfa Monotype (iType), Type Solutions, Inc. (owned by Bitstream Inc.) (Font Fusion (FFS), btX2), Fontworks (Gaiji Master), which have independently developed stroke-based font types and font engines. Although Monotype and Bitstream have claimed tremendous space saving using stroke-based fonts on East Asian character sets, most of the space saving comes from building composite glyphs, which is part of the TrueType specification and does not require a stroke-based approach. Stroke-based font formats Metafont uses a different sort of glyph description. Like TrueType, it is a vector font description system. It draws glyphs using strokes produced by moving a polygonal or elliptical pen approximated by a polygon along a path made from cubic composite Bézier curves and straight line segments, or by filling such paths. Although when stroking a path the envelope of the stroke is never actually generated, the method causes no loss of accuracy or resolution. The method Metafont uses is more mathematically complex because the parallel curves of a Bézier can be 10th order algebraic curves. In 2004, DynaComware developed DigiType, a stroke-based font format. In 2006, the creators