https://www.cnet.com/news/mac-os-10-14-leak-suggests-dark-mode-apple-news-app/

Is the Mac heading to the Dark Side? A new leak suggests that could be the case.

Software programmer Steven Troughton-Smith took to Twitter on Saturday to say he'd come across internal Apple video that shows the company's Xcode development tool running on Mac OS 10.14. That's the upcoming version of the operating system, expected to be previewed at WWDC 2018, which starts Monday.