Implementations
Some CTL implementations do not encapsulate information about specific scripts. In these implementations, the script-specific CTL information resides within the font files. Therefore, they are able to render any script:
- Apple Advanced Typography
- Graphite
Other CTL implementations encapsulate information about specific scripts. In these implementations, the script-specific CTL information is provided by the CTL implementation. Therefore, they are only able to render the scripts that are previously implemented:
- International Components for Unicode (ICU)
- Pango provides text services to GTK+
- Harfbuzz is the new OpenType layout engine for Pango and Qt
- Uniscribe and its successor, DirectWrite
Read more about this topic: Complex Text Layout