LINUSCRIBE, a rendering engine for complex scripts on Linux

Font rendering, the displaying of alphabets and characters on screen, is something that most of us take for granted, without realizing the processing, which takes place 'backstage'. This processing may be as simple as substituting the correct character shape (glyph) for a key press or as complex as making use of a sophisticated rule firing engine for complex languages and scripts such as Urdu. A sophisticated rendering engine should be a critical part of any operating system that offers multilingual support. Windows and Apple have been quick to improve their rendering engines in order to take advantage of emerging international markets. Linux, however, has been slow and inadequate in this respect. The aim of this paper is to give an overview of the various tasks of a good font rendering engine and finally present a bare bones font processing engine needed to display a broad selection of scripts and languages on Linux. However, our focus is on the rendering of our national language: Urdu.