for Microsoft Windows HarfBuzz, a cross-platform library Pango, a cross-platform library which nowadays incorporates HarfBuzz However, such software is unable to properly render any script for which it lacks instructions, which can include many minority scripts. The alternative approach is to include the rendering instructions in the font file itself. Rendering software still needs to be capable of reading and following the instructions, but this is relatively simple. Examples of this latter approach include Apple Advanced Typography (AAT) and Graphite. Both of these names encompass both the instruction format and the software supporting it; AAT is included on Apple operating systems, while Graphite is available for Microsoft Windows and Linux-based systems. The OpenType format is primarily intended for systems using the first approach (layout knowledge in the renderer, not the font), but it has a few features that assist with CTL, such as contextual ligatures. AAT and Graphite instructions can be embedded in OpenType font files. See also Typography Unicode Writing systems which require complex text layout: Arabic alphabet Most of the Brahmic family of scripts N'Ko script Tengwar (diacritics and numbers) References External links Examples of complex rendering — SIL international's examples of complex writing systems around the world Complex Text Layout — The Open Group's Desktop Technologies Supporting Indic Scripts in Mozilla — also other CTL scripts Project SILA — Graphite and Mozilla integration project CTL Architecture in Solaris — Solaris Globalization Whitepapers Complex Scripts — Microsoft Global Development and Computing Portal Theppitak's Homepage — information about Thai language processing HarfBuzz's page at Freedesktop.org D-Type Unicode Text Module — Portable software library for complex text BidiRenderer — An application that illustrates the shaping and layout of complex text in bidirectional paragraphs using FriBidi, FreeType, and HarfBuzz Tehreer-Android — A library that gives full control over text related technologies such as bidirectional algorithm, open type shaping, text typesetting and text rendering Tehreer-Cocoa — Standalone font/text engine for iOS Typesetting Indic computing Natural language and computing