This FAQ provides answers to common questions about OpenType® fonts. If you have a question that is not addressed here, please contact us.
Q. What is OpenType font format, and how does it relate to Type 1 and TrueType?
A:The OpenType format is a superset of the existing TrueType and Adobe® PostScript® Type 1 font formats. It enables improved cross-platform document portability, rich linguistic support, powerful typographic capabilities, and simplified font management requirements.
OpenType, as jointly defined by Microsoft and Adobe Systems, is technically an extension of Microsoft's TrueType Open format, which can contain either PostScript font outlines (.otf) or TrueType font outlines (.ttf). OpenType .otf fonts are recognized and rendered on-screen by a PostScript rasterizer, such as Adobe Type Manager® (ATM®), which is either installed as an add-on system software component or built directly into the operating system. Macintosh OS X, Microsoft Windows® 2000, Windows XP, and all later Windows operating systems that have built in support for OpenType and Type 1 fonts. OpenType fonts peacefully co-exist with current font formats and can be used in the same document alongside Type 1 and TrueType fonts.
Q. What are the advantages of OpenType?
A:OpenType offers several compelling advantages:
A single, cross-platform font file that can be used on both Macintosh and Windows platforms
A nearly unlimited character set based on the international Unicode encoding standard for rich linguistic support
Advanced typographic capabilities related to glyph positioning and glyph substitution that allow for the inclusion of numerous alternate glyphs — such as old-style figures, small capitals and swashes — in one font file
A compact font outline data structure for smaller font file sizes
OpenType is natively supported in Windows 2000, Windows  XP and later Windows operating systems and the Macintosh OSX operating system
OpenType advanced typographic features are supported in Adobe InDesign® CS all versions, Adobe Illustrator® CS all versions, Adobe Photoshop® CS all versions, as well as many non-Adobe applications
Q. What compression technologies are incorporated in OpenType?
A: All OpenType fonts with PostScript outlines (.otf) use Compact Font Format (CFF, or Type 2) for considerable size reduction. Although CFF is not strictly compression, since the outlines do not have to be decompressed to be rendered, the result is still more compact than Type 1. Adobe’s OpenType fonts also use subroutinization for additional size reduction. OpenType fonts with TrueType outlines (.ttf) have the option of using compression technology licensed by Microsoft.
Q. Why are there two kinds of OpenType fonts?
A: The OpenType format is the result of merging two existing formats — Type 1 and TrueType fonts — so it is important to retain the advantages of both.
Q: Does Microsoft Windows include a PostScript Type 1 rasterizer?
A: Starting with Windows 2000 and Windows XP, Microsoft operating systems include a built-in Adobe PostScript font rasterizer. These operating systems provide native support for OpenType (with either PostScript or TrueType outlines), Type 1, and TrueType.
Q. Can I still use my Type 1 or TrueType fonts if I use OpenType?
A: You can continue working as you always have. OpenType works seamlessly alongside both TrueType and Type 1 fonts. OpenType fonts simply provide more power, since they offer extended language support and advanced typographic features on platforms and applications that support extended OpenType capabilities.
Q. What does OpenType support mean? If I’m using an operating system that supports OpenType, can I use OpenType features in all my applications?
A: OpenType support consists of three types: basic OpenType support (the fonts work like any other fonts); Unicode support (access to extended language character sets); and OpenType layout support (support for advanced typographic features). Some operating systems (or operating system extensions) can provide support for one or more of these, but support for Unicode and layout features requires that an application be programmed to provide this functionality. Adobe InDesign (all versions), Adobe Illustrator and Adobe Photoshop 6.0and later support OpenType advanced typographic features.
Q. Is OpenType restricted to Western/Roman fonts?
A: No. OpenType is based on the Unicode encoding standard, which can support virtually any or all world languages. Adobe has released several Japanese OpenType fonts, as well OpenType fonts that support Arabic, Chinese, Cyrillic, Devanagari, Greek, Gurmukhi, Hebrew, Korean and Thai.
Q. As a font developer, how can I find out more about OpenType?
A: Several developer resources are available on the Adobe Solutions Network, including the OpenType section in the Type Technology Forum and the OpenType specification. Font developers interested in tools can also contact us.
Q. Will my existing fonts work with new releases of Windows?
A: Microsoft and Adobe have worked together to make sure that the transition to OpenType is smooth for customers on all versions of Windows. Users of Windows 98 and Windows NT® 4.0 can get both OpenType and Type 1 support from ATM Light. ATM Light for Windows is available for free download from the Adobe Web site. OpenType and Type 1 font support is built directly into Windows 2000, XP and later operating systems.
Q. What about the Macintosh operating system?
A: ATM Light for Macintosh is available for free download from the Adobe Web site for use with MacOS 9. Apple's Macintosh OSX operating system provides native support for OpenType fonts.
Q. Why did Adobe and Microsoft decide to co-develop a new font format?
A: The decision to work together came from a desire to provide the best solution for customers, and to provide an environment for future joint innovations. Both companies agree that merging the Type 1 and TrueType formats is the best solution for customers, because both font standards can now be supported seamlessly on both Windows and Macintosh platforms. Both outline formats have their advantages, and merging the handling of fonts allows each company to concentrate on bringing more advanced features to their customers.
Q. What technologies are Adobe and Microsoft cross-licensing?
A: Both companies have licensed their respective font rasterizers, font production tools, and conversion software. One direct result of this is native support for Type 1 and OpenType fonts in Windows 2000.
Q. Do other vendors support OpenType?
A: Yes. Virtually all font developers release fonts in OpenType as their default today.
Q. My OpenType font has real small caps, superiors, and/or subscripts, but when I use this feature in a particular application, I get simulated glyphs. Why?
A: The application is designed to create simulated glyphs for non-OpenType fonts. Either the application doesn't support OpenType layout and substitution features, or it doesn't support the particular feature you're trying to use. Contact the application vendor to let the company know you want this feature to be supported in a future version.
Q. My OpenType font includes non-Latin characters (Central European, Greek, and Cyrillic). Why can’t I access these characters in my application or operating system?
A: Extended language support can be present in the fonts, but it is dependent on Unicode support within the operating system and/or application.
Q. How does OpenType affect PostScript printers and Adobe's PostScript OEM customers?
A: OpenType development has improved both the support of Type 1 on Windows and the support of TrueType in the PostScript environment, ensuring that customers who use PostScript printers will have the best possible experience regardless of the font type used. Support for OpenType is part of the PostScript printing system, with the support of the latest AdobePS™ printer drivers and Adobe Type Manager.
Q. What do I need to run OpenType .otf fonts?
A: To use OpenType (.otf) fonts in all your applications, you must have system-level support for the fonts — either from the operating system, or ATM Light. You may also need updated PostScript printer drivers, or newer versions of some applications.
Q. Will OpenType fonts work with my existing applications, fonts, printer, computer, and OS?
A: Yes, in most environments, you can add OpenType fonts, and they will work just like regular Type 1 or TrueType fonts. Some current operating systems will require Adobe Type Manager or ATM Light. Known incompatibilities with specific versions of applications are discussed in the OpenType ReadMe.
Q. I'm a Macintosh user and received an OpenType (.otf) font from a Windows system, but it appears with a generic icon. How can I fix this?
A: The standard OpenType icon is seen when the file type is "sfnt" and the creator is "ATMC." The OTF FileTyper, a simple drag-and-drop utility, will automatically correct the file type and creator codes on OpenType files with names ending in ".otf", even in a folder. This utility is available as a free download from Adobe. OTF FileTyper was created using the MakeAutoTyper utility from the FileTyper collection.
Q. Can I use OpenType fonts over a network?
A: Yes. As long as your computer is set up to use OpenType fonts, and the server is accessible to your computer, you can use them over a network as well. In addition, the same OpenType fonts can be used on both Macintosh and Windows systems that are connected to the network. However, you should check the terms of your font license agreement to make sure that you are licensed to use the fonts over a network, and that you are not exceeding the number of users permitted by the license.