A brief history of compression on Macs

Given that it was over three years before Apple first shipped a Mac with an internal hard disk, it’s not surprising that one of its early shareware apps was Harry Chesley’s PackIt III for compressing archives of files, in 1986. At that time, the emphasis was more on working out how to archive both forks of Mac files and how to restore them, and less on achieving efficient compression.

The following year, 16 year-old Raymond Lau, then still a high school student, developed and marketed its replacement, Stuffit, which rapidly established itself as the standard, and probably the most popular shareware utility for the Mac. From 1987 until the release of Mac OS X in 2001, Stuffit had few rivals and its .sit archives were widespread across Macs, but didn’t make it to PCs or Windows until much later.

In 1988, Aladdin Systems was formed to take over development and sales of Stuffit, and in 2004 it changed name to Allume Systems, and was bought by IMSI. The following year, Allume was bought by Smith Micro Software, Inc.

Aladdin continued a shareware version as Stuffit Classic, and launched a commercial version as Stuffit Deluxe. This line-up was later augmented with a freeware decompressor Stuffit Expander that was bundled in Mac OS X until 10.4 Tiger.

Less known today are Stuffit’s self-expanding archive apps, with built-in decompressors and the extension .sea, that enabled the few Macs without a copy of Stuffit to open them with a double-click.

Until more powerful Macs of the mid-1990s, compression was performed in software and painfully slow. One of the more popular add-in cards for expandable Macs like the Macintosh II was Sigma Designs’ DoubleUp NuBus card that compressed in real time using Salient Software’s DiskDoubler.

This is Stuffit Deluxe version 8.0.2 from 2003, the year before Aladdin was renamed Allume.

Stuffit Deluxe included support for conversion to and from BinHex encoding, used for sending binary files via email without the risk of data corruption.

DropStuff was a drag-and-drop tool or droplet for compressing files into Stuffit, Zip or Tar archives, with support for encryption, and segmentation for use where file sizes were limited.

Its Zip option also preserved resource forks.

Archives in a range of formats, including RAR, could be managed in Stuffit Archive Manager, which could even schedule automatic creation of archives.

Although Aladdin launched a Mac OS X version with a new archive format, .sitx, and support for additional compression methods beyond its own proprietary formats, Stuffit entered decline by the time it was acquired by Smith Micro. Compression requirements had changed in Mac OS X, with decreasing use of resource forks, and free availability of bundled cross-platform compression tools such as GNU Gzip.

In 2007, BetterZip supported a standard set of compression formats, including 7-Zip, but never really caught on.

This is cross-platform WinZip seen in 2015, five years after its first release for the Mac. This originated as a graphical interface for PKZIP.

Apple started including compression tools in /System/Library/CoreServices, initially with BOMArchiveHelper in Mac OS X 10.3 Jaguar, which became Archive Utility that lives on today, supporting the Compress command in the Finder’s contextual menu. This uses a modified implementation of the Zip method that preserves extended attributes, successor to the resource forks of Classic Mac OS.

For many years, Mac OS X has had access to compression at a system level, but Apple has unaccountably not opened that up to developers. In modern Macs, compression is extensively used both on disk and in memory. However, in macOS Big Sur in 2020 Apple introduced AppleArchive with its system-level support for LZ4, LZMA, zlib and a proprietary implementation of LZFSE, and those are available in a new command tool aa.

Archive Utility offers a few options, and from 2020 has included support for plain and encrypted AppleArchive format.

The arrival of Apple silicon Macs has expanded options available for compression utilities to make better use of their two core types and energy efficiency. Freeware Keka now gives the user the choice.

Legacy copies of Stuffit are still available from here.