OpenType and TrueType are font formats used by computer operating systems. Fonts are collections of different styles of typefaces, such as Times New Roman or Arial that can be chosen by a computer user while creating documents. Typography is the art of print and involves selecting the proper lettering style to convey a message. The open and true type font styles each have different characteristics that are important to typographers and others creating a document.
TrueType
The font format called TrueType, developed in the late 1980s, is the easiest and most widely used application. Created jointly by Apple and Microsoft, TrueType is simple to use and is recommended for people with limited experience working with font formats. Various TrueType font styles are included with computer operating systems. The format features a process called "hinting," which offers increased legibility of fonts as they appear on a computer screen. The TrueType font system is comprised of two parts that interact with each other; the fonts, which are available in thousands of styles, and a program called a rasterizer. Additional font styles can be purchased from numerous sources, while the rasterizer is integrated into Apple operating system versions 7 and higher and is in all Microsoft Windows systems. The purpose of the rasterizer is to aid in displaying TrueType fonts properly on screens and when printing documents.
OpenType
OpenType font is a format developed more recently than TrueType, is usable across many platforms and continues to evolve. This format provides storage capability for up to 65,000 characters, allowing designers to include many add-on styles, such as small caps and alternate characters. Additionally, OpenType allows for inclusion of many different alphabets from other languages such as Latin, Greek and Japanese. The format also gives type designers the option to include accent characters and other alternate features in their font programs. OpenType font can be used on both Apple and Microsoft operating systems as each company, and others, continue to work as a partnership to further upgrade and refine the format. Unlike the TrueType format, OpenType software does not have a rasterizer. The original versions of OpenType were developed together by Adobe and Microsoft.
Compatibility
Because OpenType font formats are continuously being developed and are newer than TrueType, they are not always compatible with older operating systems and document programs. Developers attempt to make the format compatible when possible, however support for older applications is limited. The OpenType TT font versions are compatible with Windows systems and Apple Mac OS X machines that incorporate TrueType fonts, however; this version will not work with Mac OS Classic systems such as 8.x and 9.x. The OpenType PS font format requires installation of a program called Adobe Type Manager or ATM Lite when used on any computer other than Windows 2000/XP and Mac OS X.
Caution
Some versions of OpenType simply offer the ability to use the format across multiple platforms, without supplying the added character styles that may be expected. These versions of OpenType, sometimes referred to as OpenType Pro fonts, use the same traditional styles as TrueType.
