What is an OpenType font?
OpenType font technology was developed by Adobe and Microsoft as a replacement for both PostScript and TrueType fonts. OpenType fonts can be used on both Mac OS X and Windows computers, and can either contain PostScript-formatted glyph information or TrueType-formatted glyph information; applications such as Suitcase Fusion can determine if an OpenType font is based on PostScript or TrueType, but there is no difference in functionality.