The Apple Type Services for Unicode Imaging (ATSUI) is the set of services for rendering

Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...

-encoded text introduced in

Mac OS 8.5 Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It includes the largest overhaul of the classic Mac OS experience since the release of System 7, approximately six years before. It places a greater emphasis ...

and carried forward into

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac (computer), Mac computers. Within the market of ...

. It replaced the

WorldScript WorldScript is the multilingual text rendering engine for Apple Macintosh's classic Mac OS, before Mac OS X was introduced. Starting with version 7.1, Apple unified the implementation of non-Roman script systems in a programming interface called W ...

engine for legacy encodings.

Obsolescence

ATSUI was replaced by a faster and modern Unicode imaging engine called

Core Text Core Text is a Core Foundation style API in macOS, first introduced in Mac OS X v10.4, Mac OS X 10.4 Tiger, made public in Mac OS X v10.5, Mac OS X 10.5 Leopard, and introduced for the iPad with iPhone SDK 3.2. Exposing a C (programming language), ...

Mac OS X 10.5 Mac OS X Leopard (version 10.5) is the sixth major release of macOS, Apple's desktop and server operating system for Macintosh computers. Leopard was released on October 26, 2007 as the successor of Mac OS X 10.4 Tiger, and is available in t ...

(Leopard). The framework was officially deprecated with Xcode 4.6, which was released in December 2012: "Source code using ATS APIs will generate warnings while being compiled. For 10.8, there will be no loss of functionality but there could be areas where performance will suffer. Programmers are instructed to replace all their ATS code (including ATSUI) with CoreText as ATS functionality will be completely removed in future releases of OS X." However, it was actually removed in September 2022 for source code targeting only macOS 13 Ventura, and will be totally removed in macOS 14.

References

External links

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Unicode Application programming interfaces Macintosh operating systems macOS APIs Text rendering libraries {{CharacterEncoding-stub