For more information on OpenType fonts, see the following resources:
- http://www.microsoft.com/typography/tt/tt.htm. "Specifications." Provides a collection of all specifications to date. This includes specifications that Microsoft has made public in order to create OpenType fonts for complex scripts like those used in Arabic and Indic languages.
- http://www.microsoft.com/typography/otspec/default.htm. "OpenType Specification." Serves as the basis of the specifications just mentioned.
- http://www.microsoft.com/typography/developers/volt/default.htm. "Visual OpenType Layout Tool." Describes a tool for adding OpenType Layout tables to fonts and tells how to download it.
- http://www.microsoft.com/typography/default.asp. "Microsoft Typography." Contains news, updates, specifications, and information on fonts; offers free utilities and TrueType fonts.
- http://developer.apple.com/fonts/WhitePapers/GXvsOTLayout.html. "Comparing GX Line Layout and OpenType Layout." Provides comparative details of both technologies.