Updated on April 23: Sets could have some life, still. Microsoft told Laptop Mag in a statement that Sets was taken offline while it evaluates next steps for the feature, suggesting the project hasn't been outright scrapped.
Here is the full statement from a Microsoft spokesperson:
"We’ve taken Sets offline from WIP to continue to evaluate long term while also needing to prioritize other work tied to Microsoft Edge."
Windows 10 Sets was a management feature that let you use a single window to switch between programs in separate tabs. So, if you were creating a slideshow and needed photos, you could keep your Photos app and Powerpoint open on a single canvas and seamlessly switch between the two.
Sets made quite an impression on us when we demoed it last year. In fact, we said after using Sets that "it feels like Windows should have always worked this way." Unfortunately, it appears Windows is sticking to its old ways.
Sources close to ZDNet say Microsoft dropped its plans to release Sets months ago, even after the feature was tested with Windows Insiders. The decision seems to have been a response to the poor reception the feature received from testers who didn't understand or know how to use the software.
Sets would also have reportedly delayed the launch of Microsoft's Chromium-based web browser, which entered an early preview stage earlier this month. The well-received browser would have been pushed back several months in order to integrate Sets, according to an unnamed source who spoke to ZDNet.
While Microsoft hasn't officially canceled the feature, we do know that it was missing from the latest May 2019 update. Also, Microsoft Senior Program Manager Rich Turner tweeted "The Shell-provided tab experience is no more," before offering an olive branch that "adding tabs" remains a priority for Microsoft. That implies that a new form of tab management could be coming through the pipeline, though it won't be built upon the Sets feature we were all expecting.
We have reached out to Microsoft for details about the fate of Sets and will update this article if we hear back.