HarfBuzz

HarfBuzz is an open source text-shaping engine with a C API that turns fonts and strings of character codes into a form that is correctly arranged for the corresponding language and writing system. This is essentially the process of text shaping: translating a string of character codes into a properly arranged sequence of glyphs that can be rendered onto a screen or into final output form for inclusion in a document. This shaping depends on a number of factors: the input string, the active font, the script (or writing system) of the string, and the string's language. Various font formats have their own set of standard text-shaping rules. With Harfbuzz, you can properly shape all the major writing systems. HarfBuzz is cross-platform and supports all major software platforms and font formats.