WWDC is normally hectic at the best of times. From its Keynote onwards, Apple’s staff open up and tell us what they’ve been working on for the last year or more. In previous years, with physical audiences, the programme has been built around human limitations like mealtimes, audience reaction, and sheer exhaustion. One problem with this year’s virtual WWDC has been the sheer number of sessions and the volume of information which they have delivered. I just hope I’ll get a chance to work through all the more relevant ones before next June.

Most years, the major metric for Mac developers and users is whether Apple still loves the Mac. Some years we’ve come away wondering whether it wouldn’t rather be selling iPads instead. If there’s one very clear message that came across this year it’s that Apple has made its biggest investment yet in the Mac platform. So much so that I felt a little sorry for all the iOS and iPadOS developers who this year were definitely second fiddles.

The Mac’s history has been a jigsaw puzzle. Every now and then Apple puts another piece in, and what looked like random shapes suddenly assembles into a larger, more meaningful form.

Among the most interesting pieces which have been in place for many years are Apple’s role as a co-founder of what soon was to become ARM. At the time, its processor designs were primarily intended for Apple’s Newton PDA, because of their exceptionally low energy consumption. But three years earlier, its antecedent Acorn Computers had launched its own desktop PC, the Archimedes, based on its own RISC processor. Apple’s immediate need may have been for palmtop devices, but I’m sure there was considerable interest in what ARM processors could do in a full-sized computer.

When Apple’s chosen Motorola processors were starting to hold back Mac hardware development, a RISC-based future was looking more promising. The year after ARM came into being, Apple joined with IBM and Motorola to develop a different series of RISC processors, the PowerPC. Although these served well in desktop Macs, they couldn’t compete with the likes of Intel in the flourishing laptop market. In 2005, Apple officially announced that Macs would switch to Intel processors, and its PowerPC venture was dead.

Engineering development using ARM-designed processors hadn’t died, though. In 2007 came the iPhone, the most successful platform for low-powered RISC processors yet. Apple began buying stakes in companies like Imagination Technologies, who design PowerVR mobile GPUs, and bringing in the technology to design its own Systems on a Chip (SoC), most notably when it acquired P A Semi in 2008 amd Intrinsity two years later.

Software jigsaw pieces have also been plentiful. Xcode 3 in 2007 added the cross-compilers necessary to build apps for iOS and ARM processors. Standardisation on the Apple File System APFS followed across iOS devices and macOS with High Sierra in 2017. The following year came Metal graphics, and the loss of 32-bit support and division of the boot volume into System and Data volumes in Catalina last year. Developers are now being strongly encouraged to use cross-platform SwiftUI and Catalyst to enable migration of their apps between Apple’s platforms.

With all four sides of the puzzle complete, pundits argued over what went in the middle. For some, Macs were obviously going to run a desktop version of iOS, and were about to disappear as ‘serious’ computers.

WWDC has provided more jigsaw pieces than any single event in the history of the Mac. We’re still sorting them out, but the image already shows a richer future ahead. Even small details are visible. Do you remember the recent disappointment when we thought that Catalina’s new battery management would compare with that of iOS? Wait until you see what’s in store in Big Sur.

For the moment, though, there’s at least one piece missing: where does Windows fit in? Microsoft’s name came up often enough, in connection with its porting of Office 365 to the new Apple Silicon Macs, and Linux was identified running sweetly on the screen. But the W word was studiously avoided. Early during WWDC, Parallels almost gave the game away, like the small child who can’t contain a secret any longer. “Our award-winning Parallels Desktop for Mac software makes it simple for businesses and individuals to use the applications and files from any operating system they need on their Macs.”

Any operating system then? The answer we’re left with is alluring but uninforming: “We look forward to sharing more information about Parallels Desktop’s support for Mac with Apple Silicon in the future.”

There’s a great deal more to come too. Crowded out from this year’s WWDC was an account of the changes in APFS, a topic which I’ll turn to tomorrow when I explain how Big Sur’s Time Machine backups can be stored on APFS volumes, and how we’re finally getting one of the initial promises of Apple’s new file system.