Microsoft veteran Raymond Chen has revealed that Redmond's efforts to port Windows from 32-bit to 64-bit had a code name that served a second purpose: a thinly veiled dig at a rival.

Although today's Windows 11 is a 64-bit operating system, more than 20 years ago Microsoft was wrestling with how to port the code from the 32-bit world. The initial target was Intel's Itanium architecture. The problem was that back then, the chips only existed in simulators.

However, the 64-bit Alpha AXP was available, and Microsoft had quite a few systems lying around (Compaq pulled support for Windows on the hardware in 1999) so the plan became an effort to port 32-bit Windows to the 64-bit Alpha AXP.

In 2016, Chen wrote about the discovery of an old Alpha AXP machine running a 64-bit version of Windows from early 2000. His recollection this week concerns the code name of that project: "Sundown."

Microsoft loves a code name. Famous ones include "Chicago" for Windows 95, "Memphis" for Windows 98, and "Longhorn" for Vista. It isn't alone - during the recent DevOps World event in London, CloudBees CSO Sacha Labourey told The Register that an effort to bring the enterprise software maker's SaaS product and Jenkins DevOps tooling closer together had been dubbed "Convergence."

Chen said yesterday: "I hadn't given the code name much thought. Lots of projects have code names, and you rarely think deeply about the name. It's just an arbitrary collection of words to identify a project."

Except it wasn't quite so arbitrary. Sun Microsystems had recently released Solaris 7, the first 64-bit UltraSPARC release of the operating system. According to Chen: "The 64-bit version of Windows was a direct attack against Sun's early foothold, with the goal of unseating the current leader."

This was confirmed at the ship party for the work. According to Chen, the project lead took to the stage, thanked the team for their hard work, "and then finished the speech by announcing 'Sun? Down!'"

Ah ha. Chen had an epiphany: "It was then that I realized that the code name of 'Sundown' was not chosen arbitrarily. It was a jab at Sun Microsystems."

It would be another tech giant that would kill off Sun once and for all, years later - but that's another story.

And Microsoft's hoped-for dominance? History has shown us that the OS titan missed an emerging trend. Chen explained: "Today, the leading 64-bit operating system is neither Solaris nor Windows. It's Android.

"As of 2020, over 80 percent of adults in the world own a smartphone, over 70 percent of smartphones are running Android, and nearly 90 percent of Android devices use ARM64."

Well, quite. ®

https://www.theregister.com//2023/12/07/64bit_windows_code_name/