A file format is a standard way that information is encoded for storage in a computer file . It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free .
116-407: The AppleLink Package Compression Format , or AppleLink Package for short, is an obsolete file format used on Apple Inc. 's defunct AppleLink online service as a file transfer and file compression format. It was not particularly efficient and was easily outperformed by contemporary systems like StuffIt and Compact Pro , and remained rare outside AppleLink. This computing article
232-701: A 'no new features' release. Since its release, several OS X or macOS releases (namely OS X Mountain Lion , OS X El Capitan , macOS High Sierra , and macOS Monterey ) follow this pattern, with a name derived from its predecessor, similar to the ' tick–tock model ' used by Intel. In two succeeding versions, Lion and Mountain Lion , Apple moved some applications to a highly skeuomorphic style of design inspired by contemporary versions of iOS while simplifying some elements by making controls such as scroll bars fade out when not in use. This direction was, like brushed metal interfaces, unpopular with some users, although it continued
348-675: A business that attempted to profit from selling macOS on non-Apple certified hardware, was sued by Apple in 2008. In April 2002, eWeek announced a rumor that Apple had a version of Mac OS X code-named Marklar , which ran on Intel x86 processors. The idea behind Marklar was to keep Mac OS X running on an alternative platform should Apple become dissatisfied with the progress of the PowerPC platform. These rumors subsided until late in May 2005, when various media outlets, such as The Wall Street Journal and CNET , announced that Apple would unveil Marklar in
464-434: A byte frequency distribution to build the representative models for file type and use any statistical and data mining techniques to identify file types. There are several types of ways to structure data in a file. The most usual ones are described below. Earlier file formats used raw data formats that consisted of directly dumping the memory images of one or more structures into the file. This has several drawbacks. Unless
580-408: A company logo may be needed both in .eps format (for publishing) and .png format (for web sites). With the extensions visible, these would appear as the unique filenames: " CompanyLogo.eps " and " CompanyLogo.png ". On the other hand, hiding the extensions would make both appear as " CompanyLogo ", which can lead to confusion. Hiding extensions can also pose a security risk. For example,
696-740: A disadvantage due to blocking the Mac App Store's use for professional applications that require elevated privileges. Applications without any code signature cannot be run by default except from a computer's administrator account. Apple produces macOS applications. Some are included with macOS and some sold separately. This includes iWork , Final Cut Pro , Logic Pro , iLife , and the database application FileMaker . Numerous other developers also offer software for macOS . In 2018, Apple introduced an application layer, codenamed Marzipan, to port iOS apps to macOS. macOS Mojave included ports of four first-party iOS apps including Home and News , and it
812-520: A few bytes long. The metadata contained in a file header are usually stored at the start of the file, but might be present in other areas too, often including the end, depending on the file format or the type of data contained. Character-based (text) files usually have character-based headers, whereas binary formats usually have binary headers, although this is not a rule. Text-based file headers usually take up more space, but being human-readable, they can easily be examined by using simple software such as
928-448: A file based on the end of its name, more specifically the letters following the final period. This portion of the filename is known as the filename extension . For example, HTML documents are identified by names that end with .html (or .htm ), and GIF images by .gif . In the original FAT file system , file names were limited to an eight-character identifier and a three-character extension, known as an 8.3 filename . There are
1044-401: A file format is to use information regarding the format stored inside the file itself, either information meant for this purpose or binary strings that happen to always be in specific locations in files of some formats. Since the easiest place to locate them is at the beginning, such area is usually called a file header when it is greater than a few bytes , or a magic number if it is just
1160-416: A file unusable (or "lose" it) by renaming it incorrectly. This led most versions of Windows and Mac OS to hide the extension when listing files. This prevents the user from accidentally changing the file type, and allows expert users to turn this feature off and display the extensions. Hiding the extension, however, can create the appearance of two or more identical filenames in the same folder. For example,
1276-401: A formal specification document, letting precedent set by other already existing programs that use the format define the format via how these existing programs use it. If the developer of a format does not publish free specifications, another developer looking to utilize that kind of file must either reverse engineer the file to find out how to read it or acquire the specification document from
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#17328868830831392-399: A hierarchical structure, known as a conformance hierarchy. Thus, public.png conforms to a supertype of public.image , which itself conforms to a supertype of public.data . A UTI can exist in multiple hierarchies, which provides great flexibility. In addition to file formats, UTIs can also be used for other entities which can exist in macOS, including: In IBM OS/VS through z/OS ,
1508-442: A limited number of three-letter extensions, which can cause a given extension to be used by more than one program. Many formats still use three-character extensions even though modern operating systems and application programs no longer have this limitation. Since there is no standard list of extensions, more than one format can use the same extension, which can confuse both the operating system and users. One artifact of this approach
1624-414: A malicious user could create an executable program with an innocent name such as " Holiday photo.jpg.exe ". The " .exe " would be hidden and an unsuspecting user would see " Holiday photo.jpg ", which would appear to be a JPEG image, usually unable to harm the machine. However, the operating system would still see the " .exe " extension and run the program, which would then be able to cause harm to
1740-467: A new recompiled version of OS X along with Rosetta , a binary translation layer which enables software compiled for PowerPC Mac OS X to run on Intel Mac OS X machines. The system was included with Mac OS X versions up to version 10.6.8. Apple dropped support for Classic mode on the new Intel Macs. Third party emulation software such as Mini vMac , Basilisk II and SheepShaver provided support for some early versions of Mac OS. A new version of Xcode and
1856-412: A number of features, such as fast file searching and improved graphics processing, that Microsoft had spent several years struggling to add to Windows Vista with acceptable performance. As the operating system evolved, it moved away from the classic Mac OS , with applications being added and removed. Considering music to be a key market, Apple developed the iPod music player and music software for
1972-610: A number of pre-G3 Power Macintosh systems that can be made to run up to and including Mac OS X 10.2 Jaguar, all G3-based Macs which can run up to and including Tiger, and sub-867 MHz G4 Macs can run Leopard by removing the restriction from the installation DVD or entering a command in the Mac's Open Firmware interface to tell the Leopard Installer that it has a clock rate of 867 MHz or greater. Except for features requiring specific hardware such as graphics acceleration or DVD writing,
2088-408: A particular file's format, with each approach having its own advantages and disadvantages. Most modern operating systems and individual applications need to use all of the following approaches to read "foreign" file formats, if not work with them completely. One popular method used by many operating systems, including Windows , macOS , CP/M , DOS , VMS , and VM/CMS , is to determine the format of
2204-558: A performance penalty when run on Intel Macs through Rosetta. Moreover, some PowerPC software, such as kernel extensions and System Preferences plugins, are not supported on Intel Macs at all. Plugins for Safari need to be compiled for the same platform as Safari, so when Safari is running on Intel, it requires plug-ins that have been compiled as Intel-only or universal binaries, so PowerPC-only plug-ins will not work. While Intel Macs can run PowerPC, Intel, and universal binaries, PowerPC Macs support only universal and PowerPC builds. Support for
2320-464: A sense of depth. New interface elements were integrated, including sheets ( dialog boxes attached to specific windows) and drawers, which would slide out and provide options. The use of soft edges, translucent colors, and pinstripes, similar to the hardware design of the first iMacs , brought more texture and color to the user interface when compared to what Mac OS 9 and Mac OS X Server 1.0 's " Platinum " appearance had offered. According to Siracusa,
2436-441: A sorted index). Also, data must be read from the file itself, increasing latency as opposed to metadata stored in the directory. Where file types do not lend themselves to recognition in this way, the system must fall back to metadata. It is, however, the best way for a program to check if the file it has been told to process is of the correct format: while the file's name or metadata may be altered independently of its content, failing
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#17328868830832552-431: A specialized editor or IDE . However, this feature was often the source of user confusion, as which program would launch when the files were double-clicked was often unpredictable. RISC OS uses a similar system, consisting of a 12-bit number which can be looked up in a table of descriptions—e.g. the hexadecimal number FF5 is "aliased" to PoScript , representing a PostScript file. A Uniform Type Identifier (UTI)
2668-582: A system that would be adopted by Apple's primary market of home users and creative professionals. The project was first codenamed " Rhapsody " before officially being named Mac OS X. The letter "X" in Mac OS X's name refers to the number 10, a Roman numeral , and Apple has stated that it should be pronounced "ten" in this context. However, it is also commonly pronounced like the letter "X". The iPhone X , iPhone XR and iPhone XS all later followed this convention. Previous Macintosh operating systems (versions of
2784-485: A text editor or a hexadecimal editor. As well as identifying the file format, file headers may contain metadata about the file and its contents. For example, most image files store information about image format, size, resolution and color space , and optionally authoring information such as who made the image, when and where it was made, what camera model and photographic settings were used ( Exif ), and so on. Such metadata may be used by software reading or interpreting
2900-492: A trend of greater animation and variety in the interface previously seen in design aspects such as the Time Machine backup utility, which presented past file versions against a swirling nebula, and the glossy translucent dock of Leopard and Snow Leopard . In addition, with Mac OS X 10.7 Lion , Apple ceased to release separate server versions of Mac OS X, selling server tools as a separate downloadable application through
3016-495: A value in a company/standards organization database), and the 2 following digits categorize the type of file in hexadecimal . The final part is composed of the usual filename extension of the file or the international standard number of the file, padded left with zeros. For example, the PNG file specification has the FFID of 000000001-31-0015948 where 31 indicates an image file, 0015948
3132-549: A variety of professional video and image formats and includes an extensive pre-installed font library, featuring many prominent brand-name designs. The Finder is a file browser allowing quick access to all areas of the computer, which has been modified throughout subsequent releases of macOS. Quick Look has been part of the Finder since version 10.5 . It allows for dynamic previews of files, including videos and multi-page documents without opening any other applications. Spotlight ,
3248-630: A way of identifying what type of file was attached to an e-mail , independent of the source and target operating systems. MIME types identify files on BeOS , AmigaOS 4.0 and MorphOS , as well as store unique application signatures for application launching. In AmigaOS and MorphOS, the Mime type system works in parallel with Amiga specific Datatype system. There are problems with the MIME types though; several organizations and people have created their own MIME types without registering them properly with IANA, which makes
3364-428: A well-designed magic number test is a pretty sure sign that the file is either corrupt or of the wrong type. On the other hand, a valid magic number does not guarantee that the file is not corrupt or is of a correct type. So-called shebang lines in script files are a special case of magic numbers. Here, the magic number is human-readable text that identifies a specific command interpreter and options to be passed to
3480-451: Is a POSIX -compliant operating system built on top of the XNU kernel , (which incorporated large parts of FreeBSD kernel ) and FreeBSD userland for the standard Unix facilities available from the command line interface . Apple has released this family of software as a free and open source operating system named Darwin . On top of Darwin, Apple layered a number of components, including
3596-651: Is a stub . You can help Misplaced Pages by expanding it . File format Some file formats are designed for very particular types of data: PNG files, for example, store bitmapped images using lossless data compression . Other file formats, however, are designed for storage of several different types of data: the Ogg format can act as a container for different types of multimedia including any combination of audio and video , with or without text (such as subtitles ), and metadata . A text file can contain any stream of characters, including possible control characters , and
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3712-528: Is a method used in macOS for uniquely identifying "typed" classes of entities, such as file formats. It was developed by Apple as a replacement for OSType (type & creator codes). The UTI is a Core Foundation string , which uses a reverse-DNS string. Some common and standard types use a domain called public (e.g. public.png for a Portable Network Graphics image), while other domains can be used for third-party types (e.g. com.adobe.pdf for Portable Document Format ). UTIs can be defined within
3828-407: Is a risk that the file format can be misinterpreted. It may even have been badly written at the source. This can result in corrupt metadata which, in extremely bad cases, might even render the file unreadable. A more complex example of file headers are those used for wrapper (or container) file formats. One way to incorporate file type metadata, often associated with Unix and its derivatives,
3944-420: Is also the final release with PowerPC Mac support. Mac OS X 10.6 Snow Leopard was the first version of Mac OS X to be built exclusively for Intel Macs, and the final release with 32-bit Intel Mac support. The name was intended to signal its status as an iteration of Leopard, focusing on technical and performance improvements rather than user-facing features; indeed it was explicitly branded to developers as being
4060-408: Is an operating system developed and marketed by Apple since 2001. It is the primary operating system for Apple's Mac computers . Within the market of desktop and laptop computers, it is the second most widely used desktop OS , after Microsoft Windows and ahead of all Linux distributions, including ChromeOS and SteamOS . As of 2024 , the most recent release of macOS is macOS 15 Sequoia ,
4176-446: Is an extensible scheme of persistent, unique, and unambiguous identifiers for file formats, which has been developed by The National Archives of the UK as part of its PRONOM technical registry service. PUIDs can be expressed as Uniform Resource Identifiers using the info:pronom/ namespace. Although not yet widely used outside of the UK government and some digital preservation programs,
4292-594: Is encoded in one of various character encoding schemes . Some file formats, such as HTML , scalable vector graphics , and the source code of computer software are text files with defined syntaxes that allow them to be used for specific purposes. File formats often have a published specification describing the encoding method and enabling testing of program intended functionality. Not all formats have freely available specification documents, partly because some developers view their specification documents as trade secrets , and partly because other developers never author
4408-424: Is small, and/or that chunks do not contain other chunks; many formats do not impose those requirements. The information that identifies a particular "chunk" may be called many different things, often terms including "field name", "identifier", "label", or "tag". The identifiers are often human-readable, and classify parts of the data: for example, as a "surname", "address", "rectangle", "font name", etc. These are not
4524-427: Is that the system can easily be tricked into treating a file as a different format simply by renaming it — an HTML file can, for instance, be easily treated as plain text by renaming it from filename.html to filename.txt . Although this strategy was useful to expert users who could easily understand and manipulate this information, it was often confusing to less technical users, who could accidentally make
4640-637: Is the standard number and 000000001 indicates the International Organization for Standardization (ISO). Another less popular way to identify the file format is to examine the file contents for distinguishable patterns among file types. The contents of a file are a sequence of bytes and a byte has 256 unique permutations (0–255). Thus, counting the occurrence of byte patterns that is often referred to as byte frequency distribution gives distinguishable patterns to identify file types. There are many content-based file type identification schemes that use
4756-414: Is therefore unsupported by Apple technical support, warranties etc.), but communities that cater to personal users, who do not install for resale and profit, have generally been ignored by Apple. These self-made computers allow more flexibility and customization of hardware, but at a cost of leaving the user more responsible for their own machine, such as on matter of data integrity or security. Psystar ,
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4872-475: Is to store a "magic number" inside the file itself. Originally, this term was used for a specific set of 2-byte identifiers at the beginnings of files, but since any binary sequence can be regarded as a number, any feature of a file format which uniquely distinguishes it can be used for identification. GIF images, for instance, always begin with the ASCII representation of either GIF87a or GIF89a , depending upon
4988-686: The Aqua interface and the Finder , to complete the GUI -based operating system which is macOS. With its original introduction as Mac OS X, the system brought a number of new capabilities to provide a more stable and reliable platform than its predecessor, the classic Mac OS . For example, pre-emptive multitasking and memory protection improved the system's ability to run multiple applications simultaneously without them interrupting or corrupting each other. Many aspects of macOS's architecture are derived from OPENSTEP , which
5104-564: The Classic Environment with performance limitations; this feature was removed from 10.5 onwards and all Macs using Intel processors. Because macOS is POSIX compliant, many software packages written for the other Unix-like systems including Linux can be recompiled to run on it, including many scientific and technical programs. Third-party projects such as Homebrew , Fink , MacPorts and pkgsrc provide pre-compiled or pre-formatted packages. Apple and others have provided versions of
5220-629: The GIF file format required the use of a patented algorithm, and though the patent owner did not initially enforce their patent, they later began collecting royalty fees . This has resulted in a significant decrease in the use of GIFs, and is partly responsible for the development of the alternative PNG format. However, the GIF patent expired in the US in mid-2003, and worldwide in mid-2004. Different operating systems have traditionally taken different approaches to determining
5336-518: The Mac App Store , a marketplace of software maintained by Apple through a process requiring the company's approval. Apps installed through the Mac App Store run within a sandbox , restricting their ability to exchange information with other applications or modify the core operating system and its features. This has been cited as an advantage, by allowing users to install apps with confidence that they should not be able to damage their system, but also as
5452-419: The Mac App Store . Newer versions of Mac OS X also included modifications to the general interface, moving away from the striped gloss and transparency of the initial versions. Some applications began to use a brushed metal appearance, or non-pinstriped title bar appearance in version 10.4. In Leopard, Apple announced a unification of the interface, with a standardized gray-gradient window style. In 2006,
5568-781: The Mac transition to Intel processors , it was modified so that developers could build their applications as a universal binary , which provides compatibility with both the Intel-based and PowerPC-based Macintosh lines. First and third-party applications can be controlled programmatically using the AppleScript framework, retained from the classic Mac OS , or using the newer Automator application that offers pre-written tasks that do not require programming knowledge. Apple offered two main APIs to develop software natively for macOS: Cocoa and Carbon . Cocoa
5684-462: The Taligent , Copland and Gershwin projects, but all were eventually abandoned. This led Apple to acquire NeXT in 1997, allowing NeXTSTEP, later called OPENSTEP , to serve as the basis for Apple's next generation operating system. This purchase also led to Steve Jobs returning to Apple as an interim, and then the permanent CEO, shepherding the transformation of the programmer-friendly OPENSTEP into
5800-617: The X Window System graphical interface which can allow these applications to run with an approximation of the macOS look-and-feel. The current Apple-endorsed method is the open-source XQuartz project; earlier versions could use the X11 application provided by Apple, or before that the XDarwin project. Applications can be distributed to Macs and installed by the user from any source and by any method such as downloading (with or without code signing , available via an Apple developer account) or through
5916-437: The classic Mac OS ) were named using Arabic numerals , as with Mac OS 8 and Mac OS 9 . Until macOS 11 Big Sur , all versions of the operating system were given version numbers of the form 10. x , with this going from 10.0 up until 10.15; starting with macOS 11 Big Sur , Apple switched to numbering major releases with numbers that increase by 1 with every major release. The first version of Mac OS X, Mac OS X Server 1.0 ,
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#17328868830836032-650: The "NS" prefix is ubiquitous in the framework, standing variously for N eXT S TEP or N eXT/ S un . The official OPENSTEP API, published in September 1994, was the first to split the API between Foundation and ApplicationKit and the first to use the "NS" prefix. Traditionally, Cocoa programs have been mostly written in Objective-C , with Java as an alternative. However, on July 11, 2005, Apple announced that "features added to Cocoa in Mac OS X versions later than 10.4 will not be added to
6148-560: The 2010s. Rumors intensified in 2020, when numerous reports announced that the company would announce its shift to its custom processors at WWDC. Apple officially announced its shift to processors designed in-house on June 22, 2020, at WWDC 2020, with the transition planned to last for approximately two years. The first release of macOS to support ARM was macOS Big Sur . Big Sur and later versions support Universal 2 binaries , which are applications consisting of both Intel ( x86-64 ) and Apple silicon ( AArch64 ) binaries; when launched, only
6264-777: The 21st major version of macOS. Mac OS X succeeded classic Mac OS , the primary Macintosh operating system from 1984 to 2001. Its underlying architecture came from NeXT 's NeXTSTEP , as a result of Apple's acquisition of NeXT , which also brought Steve Jobs back to Apple. The first desktop version, Mac OS X 10.0 , was released on March 24, 2001. All macOS releases are UNIX 03 certified. The derivatives of macOS are Apple's other operating systems: iOS , iPadOS , watchOS , tvOS , and audioOS . macOS has supported three major processor architectures: originally PowerPC -based Macs in 1999; Intel Core-based Macs from 2006 ; and self-designed 64-bit Arm Apple M series Macs since 2020 . A prominent part of macOS's original brand identity
6380-467: The ASCII representation formed a sequence of meaningful characters, such as an abbreviation of the application's name or the developer's initials. For instance a HyperCard "stack" file has a creator of WILD (from Hypercard's previous name, "WildCard") and a type of STAK . The BBEdit text editor has a creator code of R*ch referring to its original programmer, Rich Siegel . The type code specifies
6496-459: The Aqua appearance. To some extent, Apple has used the successful transition to this new design as leverage, at various times threatening legal action against people who make or distribute software with an interface the company says is derived from its copyrighted design. Apple has continued to change aspects of the macOS appearance and design, particularly with tweaks to the appearance of windows and
6612-653: The Cocoa-Java programming interface." macOS also used to support the Java Platform as a "preferred software package"—in practice this means that applications written in Java fit as neatly into the operating system as possible while still being cross-platform compatible, and that graphical user interfaces written in Swing look almost exactly like native Cocoa interfaces. Since 2014, Apple has promoted its new programming language Swift as
6728-408: The Mac App Store. A review described the trend in the server products as becoming "cheaper and simpler... shifting its focus from large businesses to small ones." In 2012, with the release of OS X 10.8 Mountain Lion , the name of the system was officially shortened from Mac OS X to OS X, after the previous version shortened the system name in a similar fashion a year prior. That year, Apple removed
6844-583: The Mac, including iTunes and GarageBand . Targeting the consumer and media markets, Apple emphasized its new "digital lifestyle" applications such as the iLife suite, integrated home entertainment through the Front Row media center and the Safari web browser. With the increasing popularity of the internet, Apple offered additional online services, including the .Mac, MobileMe and most recently iCloud products. It later began selling third-party applications through
6960-509: The PUID scheme does provide greater granularity than most alternative schemes. MIME types are widely used in many Internet -related applications, and increasingly elsewhere, although their usage for on-disc type information is rare. These consist of a standardised system of identifiers (managed by IANA ) consisting of a type and a sub-type , separated by a slash —for instance, text/html or image/gif . These were originally intended as
7076-771: The PowerPC platform was dropped following the transition. In 2009, Apple announced at WWDC that Mac OS X 10.6 Snow Leopard would drop support for PowerPC processors and be Intel-only. Rosetta continued to be offered as an optional download or installation choice in Snow Leopard before it was discontinued with Mac OS X 10.7 Lion. In addition, new versions of Mac OS X first- and third-party software increasingly required Intel processors, including new versions of iLife, iWork, Aperture and Logic Pro. Rumors of Apple shifting Macs from Intel to in-house ARM processors used by iOS devices began circulating as early as 2011, and ebbed and flowed throughout
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#17328868830837192-715: The VSAM catalog (prior to ICF catalogs ) and the VSAM Volume Record in the VSAM Volume Data Set (VVDS) (with ICF catalogs) identifies the type of VSAM dataset. In IBM OS/360 through z/OS , a format 1 or 7 Data Set Control Block (DSCB) in the Volume Table of Contents (VTOC) identifies the Dataset Organization ( DSORG ) of the dataset described by it. The HPFS , FAT12, and FAT16 (but not FAT32) filesystems allow
7308-531: The appropriate binary is run. Additionally, Intel binaries can be run on Apple silicon-based Macs using the Rosetta 2 binary translation software. The transition was completed at WWDC 2023 with the announce of the Apple silicon Mac Pro , ending the transition in 3 years, slightly behind schedule. The change in processor architecture allows Macs with ARM processors to be able to run iOS and iPadOS apps natively. One of
7424-442: The appropriate icons, but these will be located in different places on the storage medium thus taking longer to access. A folder containing many files with complex metadata such as thumbnail information may require considerable time before it can be displayed. If a header is binary hard-coded such that the header itself needs complex interpretation in order to be recognized, especially for metadata content protection's sake, there
7540-423: The coming months. On June 6, 2005, Steve Jobs announced in his keynote address at WWDC that Apple would be making the transition from PowerPC to Intel processors over the following two years, and that Mac OS X would support both platforms during the transition. Jobs also confirmed rumors that Apple had versions of Mac OS X running on Intel processors for most of its developmental life. Intel-based Macs would run
7656-450: The command interpreter. Another operating system using magic numbers is AmigaOS , where magic numbers were called "Magic Cookies" and were adopted as a standard system to recognize executables in Hunk executable file format and also to let single programs, tools and utilities deal automatically with their saved data files, or any other kind of file types when saving and loading data. This system
7772-431: The computer. The same is true with files with only one extension: as it is not shown to the user, no information about the file can be deduced without explicitly investigating the file. To further trick users, it is possible to store an icon inside the program, in which case some operating systems' icon assignment for the executable file ( .exe ) would be overridden with an icon commonly used to represent JPEG images, making
7888-480: The cost of updates from Snow Leopard onwards, before removing upgrade fees altogether in OS X Mavericks . Some journalists and third-party software developers have suggested that this decision, while allowing more rapid feature release, meant less opportunity to focus on stability, with no version of OS X recommendable for users requiring stability and performance above new features. Apple's 2015 update, OS X 10.11 El Capitan ,
8004-419: The data must be entirely parsed by applications. On Unix and Unix-like systems, the ext2 , ext3 , ext4 , ReiserFS version 3, XFS , JFS , FFS , and HFS+ filesystems allow the storage of extended attributes with files. These include an arbitrary list of "name=value" strings, where the names are unique and a value can be accessed through its related name. The PRONOM Persistent Unique Identifier (PUID)
8120-421: The default file system is HFS+ , which it inherited from the classic Mac OS. Operating system designer Linus Torvalds had criticized HFS+, saying it is "probably the worst file system ever", whose design is "actively corrupting user data". He criticized the case insensitivity of file names, a design made worse when Apple extended the file system to support Unicode . The Darwin subsystem in macOS manages
8236-476: The default file system for SSD boot drives. Its successor, macOS 10.14 Mojave , was released in 2018, adding a dark mode option and a dynamic wallpaper setting . It was succeeded by macOS 10.15 Catalina in 2019, which replaces iTunes with separate apps for different types of media, and introduces the Catalyst system for porting iOS apps. In 2020, Apple announced macOS 11 Big Sur at that year's WWDC. This
8352-430: The destination, the single file received has to be unzipped by a compatible utility to be useful. The problems of handling metadata are solved this way using zip files or archive files. The Mac OS ' Hierarchical File System stores codes for creator and type as part of the directory entry for each file. These codes are referred to as OSTypes. These codes could be any 4-byte sequence but were often selected so that
8468-522: The display to warmer colors at night, and two Continuity features: Universal Clipboard, which syncs a user's clipboard across their Apple devices, and Auto Unlock, which can unlock a user's Mac with their Apple Watch. macOS Sierra also adds support for the Apple File System (APFS), Apple's successor to the dated HFS+ file system. macOS 10.13 High Sierra , released in 2017, included performance improvements, Metal 2 and HEVC support, and made APFS
8584-448: The early releases in retrospect as "dog-slow, feature poor" and Aqua as "unbearably slow and a huge resource hog". Apple rapidly developed several new releases of Mac OS X. Siracusa's review of version 10.3, Panther , noted "It's strange to have gone from years of uncertainty and vaporware to a steady annual supply of major new operating system releases." Version 10.4, Tiger , reportedly shocked executives at Microsoft by offering
8700-435: The file during the loading process and afterwards. File headers may be used by an operating system to quickly gather information about a file without loading it all into memory, but doing so uses more of a computer's resources than reading directly from the directory information. For instance, when a graphic file manager has to display the contents of a folder, it must read the headers of many files before it can display
8816-448: The file format's definition. Throughout the 1970s, many programs used formats of this general kind. For example, word-processors such as troff , Script , and Scribe , and database export files such as CSV . Electronic Arts and Commodore - Amiga also used this type of file format in 1985, with their IFF (Interchange File Format) file format. A container is sometimes called a "chunk" , although "chunk" may also imply that each piece
8932-476: The file system, which includes the Unix permissions layer. In 2003 and 2005, two Macworld editors expressed criticism of the permission scheme; Ted Landau called misconfigured permissions "the most common frustration" in macOS, while Rob Griffiths suggested that some users may even have to reset permissions every day, a process which can take up to 15 minutes. More recently, another Macworld editor, Dan Frakes, called
9048-809: The file, each of which is a string, such as "Plain Text" or "HTML document". Thus a file may have several types. The NTFS filesystem also allows storage of OS/2 extended attributes, as one of the file forks , but this feature is merely present to support the OS/2 subsystem (not present in XP), so the Win32 subsystem treats this information as an opaque block of data and does not use it. Instead, it relies on other file forks to store meta-information in Win32-specific formats. OS/2 extended attributes can still be read and written by Win32 programs, but
9164-444: The first Intel Macs were released with a specialized version of Mac OS X 10.4 Tiger . A key development for the system was the announcement and release of the iPhone from 2007 onwards. While Apple's previous iPod media players used a minimal operating system, the iPhone used an operating system based on Mac OS X, which would later be called " iPhone OS " and then iOS . The simultaneous release of two operating systems based on
9280-471: The format of the file, while the creator code specifies the default program to open it with when double-clicked by the user. For example, the user could have several text files all with the type code of TEXT , but each open in a different program, due to having differing creator codes. This feature was intended so that, for example, human-readable plain-text files could be opened in a general-purpose text editor, while programming or HTML code files would open in
9396-463: The format will be identified correctly, and can often determine more precise information about the file. Since reasonably reliable "magic number" tests can be fairly complex, and each file must effectively be tested against every possibility in the magic database, this approach is relatively inefficient, especially for displaying large lists of files (in contrast, file name and metadata-based methods need to check only one piece of data, and match it against
9512-586: The format's developers for a fee and by signing a non-disclosure agreement . The latter approach is possible only when a formal specification document exists. Both strategies require significant time, money, or both; therefore, file formats with publicly available specifications tend to be supported by more programs. Patent law, rather than copyright , is more often used to protect a file format. Although patents for file formats are not directly permitted under US law, some formats encode data using patented algorithms . For example, prior to 2004, using compression with
9628-410: The head of OS X development, Scott Forstall , and design was changed towards a more minimal direction. Apple's new user interface design, using deep color saturation, text-only buttons and a minimal, 'flat' interface, was debuted with iOS 7 in 2013. With OS X engineers reportedly working on iOS 7, the version released in 2013, OS X 10.9 Mavericks , was something of a transitional release, with some of
9744-484: The introduction of Aqua and its departure from the then conventional look "hit like a ton of bricks." Bruce Tognazzini (who founded the original Apple Human Interface Group) said that the Aqua interface in Mac OS X 10.0 represented a step backwards in usability compared with the original Mac OS interface. Third-party developers started producing skins for customizable applications and other operating systems which mimicked
9860-515: The main data and the name, but is also less portable than either filename extensions or "magic numbers", since the format has to be converted from filesystem to filesystem. While this is also true to an extent with filename extensions— for instance, for compatibility with MS-DOS 's three character limit— most forms of storage have a roughly equivalent definition of a file's data and name, but may have varying or no representation of further metadata. Note that zip files or archive files solve
9976-572: The major differences between the classic Mac OS and the current macOS was the addition of Aqua , a graphical user interface with water-like elements, in the first major release of Mac OS X. Every window element, text, graphic, or widget is drawn on-screen using spatial anti-aliasing technology. ColorSync , a technology introduced many years before, was improved and built into the core drawing engine, to provide color matching for printing and multimedia professionals. Also, drop shadows were added around windows and isolated text elements to provide
10092-579: The major version number, similarly to classic Mac OS and iOS, but is still named after places within California. The heritage of what would become macOS had originated at NeXT , a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, before being launched in 1989. The kernel of NeXTSTEP is based upon the Mach kernel , which
10208-430: The memory images also have reserved spaces for future extensions, extending and improving this type of structured file is very difficult. It also creates files that might be specific to one platform or programming language (for example a structure containing a Pascal string is not recognized as such in C ). On the other hand, developing tools for reading and writing these types of files is very simple. The limitations of
10324-801: The menu bar. Since 2012, Apple has sold almost all of its Mac models with high-resolution Retina displays , and macOS and its APIs have extensive support for resolution-independent development on supporting high-resolution displays. Reviewers have described Apple's support for the technology as superior to that on Windows. The human interface guidelines published by Apple for macOS are followed by many applications, giving them consistent user interface and keyboard shortcuts. In addition, new services for applications are included, which include spelling and grammar checkers, special characters palette, color picker, font chooser and dictionary; these global features are present in every Cocoa application, adding consistency. The graphics system OpenGL composites windows onto
10440-472: The operating system offers the same functionality on all supported hardware. As most Mac hardware components, or components similar to those, since the Intel transition are available for purchase, some technology-capable groups have developed software to install macOS on non-Apple computers. These are referred to as Hackintoshes , a portmanteau of the words "hack" and "Macintosh". This violates Apple's EULA (and
10556-588: The preferred language for software development on Apple platforms. Apple's original plan with macOS was to require all developers to rewrite their software into the Cocoa APIs. This caused much outcry among existing Mac developers, who threatened to abandon the platform rather than invest in a costly rewrite, and the idea was shelved. To permit a smooth transition from Mac OS 9 to Mac OS X, the Carbon Application Programming Interface (API)
10672-416: The problem of handling metadata. A utility program collects multiple files together along with metadata about each file and the folders/directories they came from all within one new file (e.g. a zip file with extension .zip ). The new file is also compressed and possibly encrypted, but now is transmissible as a single file across operating systems by FTP transmissions or sent by email as an attachment. At
10788-646: The procedure of repairing permissions vastly overused. He argues that macOS typically handles permissions properly without user interference, and resetting permissions should only be tried when problems emerge. The architecture of macOS incorporates a layered design: the layered frameworks aid rapid development of applications by providing existing code for common tasks. Apple provides its own software development tools, most prominently an integrated development environment called Xcode . Xcode provides interfaces to compilers that support several programming languages including C , C++ , Objective-C , and Swift . For
10904-447: The program look like an image. Extensions can also be spoofed: some Microsoft Word macro viruses create a Word file in template format and save it with a .doc extension. Since Word generally ignores extensions and looks at the format of the file, these would open as templates, execute, and spread the virus. This represents a practical problem for Windows systems where extension-hiding is turned on by default. A second way to identify
11020-473: The release of Leopard onwards and announced that Carbon applications would not run at 64-bit. A number of macOS applications continued to use Carbon for some time afterwards, especially ones with heritage dating back to the classic Mac OS and for which updates would be difficult, uneconomic or not necessary. This included Microsoft Office up to Office 2016 , and Photoshop up to CS5. Early versions of macOS could also run some classic Mac OS applications through
11136-471: The same frameworks placed tension on Apple, which cited the iPhone as forcing it to delay Mac OS X 10.5 Leopard . However, after Apple opened the iPhone to third-party developers its commercial success drew attention to Mac OS X, with many iPhone software developers showing interest in Mac development. In 2007, Mac OS X 10.5 Leopard was the sole release with universal binary components, allowing installation on both Intel Macs and select PowerPC Macs. It
11252-815: The same thing as identifiers in the sense of a database key or serial number (although an identifier may well identify its associated data as such a key). With this type of file structure, tools that do not know certain chunk identifiers simply skip those that they do not understand. Depending on the actual meaning of the skipped data, this may or may not be useful ( CSS explicitly defines such behavior). This concept has been used again and again by RIFF (Microsoft-IBM equivalent of IFF), PNG, JPEG storage, DER ( Distinguished Encoding Rules ) encoded streams and files (which were originally described in CCITT X.409:1984 and therefore predate IFF), and Structured Data Exchange Format (SDXF) . Indeed, any data format must somehow identify
11368-550: The screen to allow hardware-accelerated drawing. This technology, introduced in version 10.2, is called Quartz Extreme , a component of Quartz . Quartz's internal imaging model correlates well with the Portable Document Format (PDF) imaging model, making it easy to output PDF to multiple devices. As a side result, PDF viewing and creating PDF documents from any application are built-in features. Reflecting its popularity with design users, macOS also has system support for
11484-601: The significance of its component parts, and embedded boundary-markers are an obvious way to do so: This is another extensible format, that closely resembles a file system ( OLE Documents are actual filesystems), where the file is composed of 'directory entries' that contain the location of the data within the file itself as well as its signatures (and in certain cases its type). Good examples of these types of file structures are disk images , executables , OLE documents TIFF , libraries . MacOS macOS , originally Mac OS X , previously shortened as OS X ,
11600-425: The skeuomorphic design removed, while most of the general interface of Mavericks remained unchanged. The next version, OS X 10.10 Yosemite , adopted a design similar to iOS 7 but with greater complexity suitable for an interface controlled with a mouse. From 2012 onwards, the system has shifted to an annual release schedule similar to that of iOS and Mac OS X releases prior to 10.4 Tiger . It also steadily cut
11716-583: The standard to which they adhere. Many file types, especially plain-text files, are harder to spot by this method. HTML files, for example, might begin with the string <html> (which is not case sensitive), or an appropriate document type definition that starts with <!DOCTYPE html , or, for XHTML , the XML identifier, which begins with <?xml . The files can also begin with HTML comments, random text, or several empty lines, but still be usable HTML. The magic number approach offers better guarantees that
11832-438: The storage of "extended attributes" with files. These comprise an arbitrary set of triplets with a name, a coded type for the value, and a value, where the names are unique and values can be up to 64 KB long. There are standardized meanings for certain types and names (under OS/2 ). One such is that the ".TYPE" extended attribute is used to determine the file type. Its value comprises a list of one or more file types associated with
11948-472: The underlying command-line compilers supported building universal binaries that would run on either architecture. PowerPC-only software is supported with Apple's official binary translation software, Rosetta , though applications eventually had to be rewritten to run properly on the newer versions released for Intel processors. Apple initially encouraged developers to produce universal binaries with support for both PowerPC and Intel. PowerPC binaries suffer
12064-414: The unstructured formats led to the development of other types of file formats that could be easily extended and be backward compatible at the same time. In this kind of file structure, each piece of data is embedded in a container that somehow identifies the data. The container's scope can be identified by start- and end-markers of some kind, by an explicit length field somewhere, or by fixed requirements of
12180-463: The use of this standard awkward in some cases. File format identifiers are another, not widely used way to identify file formats according to their origin and their file category. It was created for the Description Explorer suite of software. It is composed of several digits of the form NNNNNNNNN-XX-YYYYYYY . The first part indicates the organization origin/maintainer (this number represents
12296-401: Was a descendant of APIs inherited from OPENSTEP with no ancestry from the classic Mac OS , while Carbon was an adaptation of classic Mac OS APIs, allowing Mac software to be minimally rewritten to run natively on Mac OS X. The Cocoa API was created as the result of a 1993 collaboration between NeXT Computer and Sun Microsystems . This heritage is highly visible for Cocoa developers, since
12412-490: Was a transitional product, featuring an interface resembling the classic Mac OS , though it was not compatible with software designed for the older system. Consumer releases of Mac OS X included more backward compatibility . Mac OS applications could be rewritten to run natively via the Carbon API ; many could also be run directly through the Classic Environment with a reduction in performance. The consumer version of Mac OS X
12528-527: Was announced that the API would be available for third-party developers to use from 2019. With macOS Catalina in 2019, the application layer was made available to third-party developers as Mac Catalyst . List of macOS versions, the supported systems on which they run, and their RAM requirements Tools such as XPostFacto and patches applied to the installation media have been developed by third parties to enable installation of newer versions of macOS on systems not officially supported by Apple. This includes
12644-402: Was announced to focus specifically on stability and performance improvements. In 2016, with the release of macOS 10.12 Sierra , the name was changed from OS X to macOS with the purpose of aligning it with the branding of Apple's other primary operating systems: iOS , watchOS , and tvOS . macOS Sierra added Siri , iCloud Drive , picture-in-picture support, a Night Shift mode that switches
12760-401: Was created. Applications written with Carbon were initially able to run natively on both classic Mac OS and Mac OS X, although this ability was later dropped as Mac OS X developed. Carbon was not included in the first product sold as Mac OS X: the little-used original release of Mac OS X Server 1.0 , which also did not include the Aqua interface. Apple limited further development of Carbon from
12876-463: Was designed to be portable, to ease the transition from one platform to another. For example, NeXTSTEP was ported from the original 68k -based NeXT workstations to x86 and other architectures before NeXT was purchased by Apple, and OPENSTEP was later ported to the PowerPC architecture as part of the Rhapsody project . Prior to macOS High Sierra, and on drives other than solid state drives (SSDs),
12992-413: Was launched in 2001 with Mac OS X 10.0 . Reviews were variable, with extensive praise for its sophisticated, glossy Aqua interface , but criticizing it for sluggish performance. With Apple's popularity at a low, the maker of FrameMaker , Adobe Inc. , declined to develop new versions of it for Mac OS X. Ars Technica columnist John Siracusa, who reviewed every major OS X release up to 10.10, described
13108-487: Was originally developed at Carnegie Mellon University , with additional kernel layers and low-level user space code derived from parts of FreeBSD and other BSD operating systems. Its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language. Throughout the 1990s, Apple had tried to create a "next-generation" OS to succeed its classic Mac OS through
13224-625: Was the first increment in the primary version number of macOS since the release of Mac OS X Public Beta in 2000; updates to macOS 11 were given 11.x numbers, matching the version numbering scheme used by Apple's other operating systems. Big Sur brought major changes to the user interface and was the first version to run on Apple Silicon , based on the ARM architecture. The numbering system started with Big Sur continued in 2021 with macOS 12 Monterey , 2022 with macOS 13 Ventura , 2023 with macOS 14 Sonoma , and 2024 with macOS 15 Sequoia . At macOS's core
13340-506: Was the use of Roman numeral X, pronounced "ten", as well as code naming each release after species of big cats , and later, places within California . Apple shortened the name to "OS X" in 2011 and then changed it to "macOS" in 2016 to align with the branding of Apple's other operating systems. After sixteen distinct versions of macOS 10, macOS Big Sur was presented as version 11 in 2020, and every subsequent version has also incremented
13456-567: Was then enhanced with the Amiga standard Datatype recognition system. Another method was the FourCC method, originating in OSType on Macintosh, later adapted by Interchange File Format (IFF) and derivatives. A final way of storing the format of a file is to explicitly store information about the format in the file system, rather than within the file itself. This approach keeps the metadata separate from both
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