To make its graphical interface work, the Mac needed a high-performance graphics system, for which the late Bill Atkinson (1951-2025) and Andy Hertzfeld designed and implemented QuickDraw. When it came to driving printers, though, Steve Jobs licensed the new page description language PostScript from Adobe, where it had just been developed by John Warnock (1940-2023), Charles Geschke (1939-2021) and others. PostScript is a stack-based interpreted language that could take many seconds or even minutes to image a page for printing, so wasn’t practical for doing much else at that time.

In the early 1990s, as desktop publishing became dominant among Mac users and we were all sending one another faxes, several companies recognised the need for a universal document format that could display laid-out text and graphics. Among them was Adobe, where Warnock formulated the aims of what he then referred to as Interchange PostScript or IPS, and so led the development of Portable Document Format. It’s telling that the final sentence of his proposal reads: “In any event corporations should be interested in site-licensing arrangements.”

When the first version of PDF was released in 1993, with its Carousel reader app, it faced competition from other similar ideas, and Adobe found itself competing against products including Farallon’s Replica, and Tumbleweed’s Envoy that gained the support of WordPerfect, then a popular cross-platform word processor. PDF didn’t become dominant until Adobe distributed its reader app free, rather than charging $50 for it as it had initially.

For many years, the only way to create really good PDFs was using Adobe’s Acrobat Distiller app, costing $695 for a single-user licence. That ingested PostScript files, created on the Mac by printing to a file, and transformed them into PDFs that could in turn only be read using Adobe’s software. Although PostScript was by then a prerequisite for all publishing work on Macs, it wasn’t until 1996, when PDF reached version 1.2 in Acrobat 3.0, that it captured the prepress market, which it consolidated in 1998 with the PDF/X-1 standard.

This is Acrobat Distiller 4.0 running on Mac OS 9.1 in early 2001, showing a few of its bewildering array of options for turning PostScript files into PDF.

At the same time, John Warnock’s aspirations for success in enterprise markets were being realised, and PDF steadily became the standard for fixed-format electronic documents, with the support of the US Internal Revenue Service and Adobe’s free cross-platform Acrobat Reader.

When Steve Jobs established NeXT in 1985 he must have become the only person to have licensed PostScript from Adobe twice, as NeXTSTEP adopted Display PostScript as the centrepiece of its graphics, developed collaboratively between NeXT and Adobe. At the time many thought this to be a mistake, as PostScript isn’t as efficient a graphics language as QuickDraw, despite Adobe’s efforts to accelerate it.

When NeXT and Mac merged to form the beginnings of Mac OS X in 1997, Display PostScript was replaced with PDF as the central graphics standard for both display and printing, in what was dubbed Quartz 2D. This was first demonstrated at WWDC in 1999 and lives on today in macOS. At the time, Apple’s in-house PDF engine in Quartz was one of few, alongside Adobe’s.

Prior to Mac OS X, Adobe Acrobat, both in its free viewer form and a paid-for Pro version, had been the de facto standard for reading, printing and working with PDF documents on the Mac. The Preview app had originated in NeXTSTEP in 1989 as its image and PDF viewer, and was brought across to early versions of Mac OS X, where it has remained ever since.

This PDF shows Apple’s original iPod promotional literature from late 2001.

Adobe continued providing its free Acrobat Reader for Mac OS X, here seen in 10.0 Cheetah.

The full paid-for version of Adobe Acrobat provided an extensive suite of editing tools, here in Mac OS X 10.1 Puma in early 2002.

By Mac OS X 10.3 Panther in 2003, Apple was claiming that Preview was “the fastest PDF viewer on the planet”, capable of navigating and searching text within PDF documents “at lightning speed”. This worked with the Mac’s new built-in support for faxing, which rendered received faxes in PDF to make them easier and clearer to access.

This is an early Keynote Quick Reference guide from 2003, viewed in Preview.

At that time, Preview was also able to convert Encapsulated PostScript (EPS) files and raw PostScript to PDF, so they could be saved in the more accessible format, and printed easily.

This page from the 9/11 Commission Report of 22 July 2004 is being viewed in Preview.

Acrobat Distiller remained an important component in Adobe’s paid-for product, even though Mac OS X was capable of generating its own PDFs. It’s seen here in Mac OS X 10.4 Tiger in 2005.

This is Acrobat Pro in 10.4 Tiger in early 2006, showing its long list of supported export formats.

Since those heady days, Preview has been relatively neglected. Revision of both the Quartz PDF engine and its API brought a spate of bugs that only abated with macOS Sierra. Preview has adopted an uncommon model for PDF annotations that often doesn’t work well with other PDF products, but it has remained very popular for completing electronic forms. Then, in macOS Ventura, Apple removed all support for converting EPS and PostScript to PDF, most probably as a result of security concerns, and their progressive disuse.

Although rumours of the death of Preview continue to prove unfounded, it’s unlikely to feature again as one of the strengths of macOS.

References

John Warnock (1991) The Camelot Project, on the Internet Archive’s Wayback machine.
Laurens Leurs’ The history of PDF.

A cynic might summarise the history of Mac OS in four eras:

1. rebuilding the Desktop (Classic Mac OS)
2. repairing system permissions (Mac OS X to OS X 10.10)
3. resetting Home permissions (OS X 10.11 to macOS 10.15)
4. cursing privacy protection (macOS 11 onwards).

There is slight overlap between the last two, in macOS 10.14 and 10.15.

Rebuilding the Desktop

Classic Mac OS built its Desktop illusion using hidden databases that associated types of document with icons set by the apps that created them. This was based on two four-character codes in every file to specify the file’s type and creator. Periodically, those databases became damaged and this association stopped working, with the result that all documents were displayed with the same generic icon.

Rebuilding those Desktop databases was initiated by restarting the Mac while holding the Command and Option keys until the dialog was shown. Mac OS then checked through all installed apps to reconstruct their associations with document types.

This had to be repeated for each volume in turn as it was mounted by Mac OS. If there wasn’t sufficient free space on a volume, the process failed. The price of some utilities like TechTool Pro was often justified by the tools they provided for assisting in this process.

Mac OS X ended that reliance on Desktop databases, leaving this to die with Classic Mac OS.

Repairing system permissions

Since its first beta-release, Mac OS X suffered from ill-defined and pervasive problems thought to result from corruption of files used by the system. Until the introduction of System Integrity Protection (SIP) in 10.11 El Capitan, those generally resulted from files within the system acquiring incorrect permissions. Various reasons were proposed for this, including installer scripts that overstepped their bounds.

To address this, Disk Utility had a feature whereby it could check and repair permissions of all major parts of the system, based on information contained in BoM files for system updates and installations. Repairing permissions in this way became one of the main panaceas in older versions of Mac OS X and OS X, and was an important feature in Disk Utility.

Although chiefly intended to provide better security protection, one of the benefits of SIP was that it largely prevented system files from gaining incorrect permissions, and the feature to repair them was removed from Disk Utility. In any case, because of SIP it was no longer possible for Disk Utility to change the permissions of files protected by SIP.

Resetting Home permissions

When macOS 10.12 Sierra was released, a different problem appeared, in which permissions apparently became set incorrectly not in system files generally, but in the user’s Home folder, and specifically in ~/Library/Preferences. To address this Apple added a new verb to the already complex command tool diskutil, resetUserPermissions, and described how to use this in a support note. It’s perhaps no coincidence that this new problem appeared at about the same time that cfprefsd took on the management of those preference files.

At that time, the following problems were attributed by Apple to incorrect permissions in ~/Library/Preferences:

• changes to preference settings, particularly those for System Preferences, do not ‘stick’;
• changes made to the Dock do not ‘stick’;
• you are asked to authenticate when trying to move or alter some folders in your Home folder;
• when trying to save, you are told that the file is locked, or that you don’t have permission;
• Preview, TextEdit, and App Store apps (which are sandboxed) may crash when opened;
• alerts appear warning that the startup disk has no more space available for app memory;
• Safari or SafariDAVClient use large amounts of resources (memory);
• the Mac runs very slowly;
• iTunes cannot sync a device;
• there are problems with Photos or iPhoto libraries, including inability to import into the library, or forgetting the library each time the app is opened.

Most if not all of those could be attributable to problems arising from bugs in cfprefsd.

Apple later changed its recommendations to include running a new tool repairHomePermissions in Recovery mode, then re-installing macOS. Shortly afterwards, in June 2020 when Big Sur was in beta, Apple withdrew that support note and all reference to repairing permissions, although the tool is still available in Recovery mode even on Apple silicon Macs.

Cursing privacy protection

Prior to macOS 10.14 Mojave, privacy protection had been limited and largely unobtrusive. We then began to discover that our favourite apps were being locked out of accessing files in many of our working folders.

Thus the era of adding apps to the Full Disk Access list started, and we came to curse the blessing of privacy protection.

Even better, Apple later added extended attributes that could prevent apps perfectly capable of editing documents from being able to save them just when we needed that most. And protected the extended attribute using SIP.

Maybe rebuilding the Desktop databases every couple of months wasn’t so bad after all?

Spotlight, the current search feature in macOS, does far more than find locally stored files, but in this brief history I focus on that function, and how it has evolved as Macs have come to keep increasingly large numbers of files.

Until early Macs had enough storage to make this worthwhile, there seemed little need. Although in 1994 there were precious few Macs with hard disks as large as 1 GB, networks could provide considerably more. That year Apple offered its first product in AppleSearch, based on a client-server system running over AppleShare networks, and in its Workgroup Servers in particular. This was a pioneering product that was soon accompanied by a local app, Find File, written by Bill Monk and introduced in System 7.5 that September.

Sherlock

The next step was to implement a similar architecture to AppleSearch on each Mac, with a service that maintained indexes of file metadata and contents, and a client that passed queries to it. This became Sherlock, first released in Mac OS 8.5 in 1998. As access to the web grew, this came to encompass remote search through plug-ins that worked with web search engines.

Those were expanded in Sherlock 2, part of Mac OS 9.0 from 1999 and shown above, and version 3 that came in Mac OS X 10.2 Jaguar in 2002. The latter brought one of the more unseemly conflicts in Apple’s history, when developers at Karelia claimed Sherlock 3 had plagiarised its own product, Watson, which in turn had been modelled on Sherlock. Apple denied that, but the phrase being Sherlocked has passed into the language as a result.

Spotlight

Sherlock remained popular with the introduction of Mac OS X, but was never ported to run native on Intel processors. Instead, Apple replaced it with Spotlight in Mac OS X 10.4 Tiger, in April 2005.

Initially, the Spotlight menu command dropped down a search panel as shown here, rather than opening a window as it does now.

A Finder search window, precursor to the modern Find window, is shown in the lower left of this screenshot taken from Tiger in 2006.

Spotlight was improved again in Mac OS 10.5 Leopard, in 2007. This extended its query language, and brought support for networked Macs that were using file sharing.

This shows a rather grander Finder search window from Mac OS X 10.5 Leopard in 2009.

Search attributes available for use in the search window are shown here in OS X 10.9 Mavericks, in 2014.

Spotlight’s last major redesign came in OS X 10.10 Yosemite, in 2014, when web and local search were merged into Global Spotlight, the search window that opens using the Spotlight icon at the right end of the menu bar. With Global Spotlight came Spotlight (then Siri from macOS Sierra) Suggestions, and they have been accompanied by remote data collection designed to preserve the relative anonymity of the user.

This Finder window in OS X 10.10 Yosemite, in 2015, shows a more complex search in progress.

This shows a search in Global Spotlight in macOS 10.12 Sierra, in 2017.

Local Search in the Finder’s Find window can now use a wide variety of attributes, some of which are shown here, in macOS 10.13 High Sierra, in 2018. Below are search bars for several different classes of metadata.

Over the years, Spotlight’s features have become more divided, in part to safeguard privacy, and to deliver similar features from databases. Core Spotlight now provides search features within apps such as Mail and Notes, where local searches lack access.

Spotlight’s indexes are located at the root level of each indexed volume, in the hidden .Spotlight-V100 folder. Those are maintained by mdworker processes relying on mdimporter plugins to provide tailored access for different file types. If an mdimporter fails to provide content data on some or all of the file types it supports, those are missing from that volume’s indexes, and Spotlight search will be unsuccessful. This happened most probably in macOS Catalina 10.15.6, breaking the indexing of content from Rich Text files. That wasn’t fixed until macOS Big Sur 11.3 in April 2021.

Over the last few years, macOS has gained the ability to perform optical character recognition using Live Text, and to analyse and classify images. Text and metadata retrieved by the various services responsible are now included in Spotlight’s indexes. From macOS 13 Ventura in 2022, those services can take prolonged periods working through images and file types like PDF that include images they can process to generate additional content and metadata for indexing.

Those with large collections of eligible files have noticed sustained workloads as a result. Fortunately for those with Apple silicon Macs, those services, like Spotlight’s indexing, run almost exclusively on their Mac’s E cores, so have little or no effect on its ability to run apps. For those with Intel processors, though, this may continue to be troubling.

In less than 30 years, searching Macs has progressed from the basic Find File to Spotlight finding search terms in text recognised in photos, in almost complete silence. Even Spotlight’s 20th birthday passed just over a month ago, on 29 April, without so much as an acknowledgment of its impact.