Specifications

Appendix E: International
Language Support
Because Mac OS X takes advantage of Unicode—an international computer standard
for representing the written languages of all cultures—it is not limited to Roman
alphabets. Applications that support Unicode can select characters from a set of
up to 65,636 different symbols—almost one glyph for every possible character in
every written language. Most fonts don’t need so many symbols, but many non-
Roman fonts used in Asia and the Middle East require thousands of different glyphs.
Like ASCII, Unicode is a character encoding system, but Unicode provides a unique
number for every character regardless of platform, program, or language. Think of
Unicode like assigned seating in a classroom: The person whose last name starts
with “A” is always followed by the person whose last name starts with “B,” and they
cannot change seats.
The Unicode Standard supports 917,631 characters—enough for all the world’s
languages and symbols. The starting point for ASCII, or what was known as Mac
encoding, was 256 characters. This was extremely limiting for languages that contain
more than a thousand characters, such as Simplified Chinese.
The solution to this limitation has come from the Unicode Consortium, a nonprofit
organization that specifies how text is represented in modern software products and
standards. Along with Apple, consortium members include HP, IBM, Microsoft, Oracle,
SAP, Sun, Sybase, and Unisys. Today the Unicode Standard is supported in many
operating systems, all modern browsers, and many other products. It represents
one of the most significant advances in global software technology.
As long as an application supports Unicode, this powerful standard allows you to
include characters from different languages and different alphabets in a single
document or web page and deliver it over multiple platforms, languages, and coun-
tries. You do not need to install or reconfigure software to display a wide range of
characters and alphabets correctly if you use the default font installation. For example,
the extended font set supplied in Mac OS X supports 26 languages, including Central
European, Baltic, Greek, Turkish, Cyrillic, and Simplified Chinese. Mac OS X also provides
one of the most complete font sets for CJK (Chinese, Japanese, and Korean) fonts—as
many as 32,500 characters in the Simplified Chinese font alone.
The Unicode Standard assigns a range of numbers, or “tags,” for a character group.
For example, the characters A–Z are assigned the range 65–90. Greek characters are
assigned the range 880–1023. In the past, Western font designers wanting to display
Greek characters would simply insert the Greek “alpha” in the “a” cell, the Greek “beta”
in the “b” cell, and so on. Today savvy font manufacturers use the official Unicode
designation for each character. Dingbats and symbols are also used so commonly in
multiple languages that the Unicode Consortium assigned these characters their own
34
Technology Tour
Advanced Typography
with Mac OS X
Using the Input menu with
international fonts
To make it easy to select keyboard lay-
outs that correspond to different fonts,
Mac OS X provides the Input menu. This
menu (located in the International pane
in System Preferences) shows different
keyboard layouts so that you can use the
same keyboard to select different glyphs.
You can use the Input menu to turn dif-
ferent keyboard layouts—including the
Character Palette—on and off. You can
also use keyboard layouts to translate
key patterns.