Windows XP had a secret Mac-flavored theme hidden away in its source code

(Image credit: The Verge / Tom Warren)

An investigation into leaked source code for Microsoft’s Windows XP has surfaced a handful of unreleased and partially complete themes built early in the operating system’s development cycle.

One theme in particular - called Candy - caught the eye of The Verge, because it bears a striking resemblance to Apple’s Aqua UI for Mac computers.

The Mac-flavored theme is incomplete, but the Start Menu and navigation buttons are quite clearly an homage to Apple’s now iconic aesthetic, which was itself unveiled roughly 18 months prior to the release of XP.

The theme is described as a “Whistler skin with eye candy” (“Whistler” being the codename for Windows XP) and is designated for “internal use only”.

It appears to have been used as a temporary theme during the development process, while Microsoft was working on the Windows XP theme engine that later allowed third-parties to overlay their own designs.

Windows XP source code

The Mac-like Windows XP theme was discovered after source code for the 19-year-old operating system was published to bulletin board website 4chan.

The 43GB data dump also included source code for Windows 2000 and multiple versions of Windows CE, MS DOS, Windows Embedded and Windows NT - plus a section dedicated to conspiracy videos aimed at Microsoft founder Bill Gates.

It has been suggested the source code leak might pose a security threat, especially given the surprising prevalence of Windows XP today (estimates suggest roughly 25 million PCs still run the OS).

According to the individual responsible for the leak, though, Windows XP source code has been circulating within hacking communities for years now, which suggests major new security vulnerabilities are unlikely to be uncovered.

However, this doesn’t rule out the discovery of further easter eggs like the Candy theme. It remains to be seen what else might be uncovered as the newly public files undergo further scrutiny.

Joel Khalili
News and Features Editor

Joel Khalili is the News and Features Editor at TechRadar Pro, covering cybersecurity, data privacy, cloud, AI, blockchain, internet infrastructure, 5G, data storage and computing. He's responsible for curating our news content, as well as commissioning and producing features on the technologies that are transforming the way the world does business.