Charles Simonyi, the creator of the world’s first WYSIWYG word processor and the “Hungarian notation” style of writing programming code, is returning to Microsoft. He is also famous for having started Microsoft’s Office product lines when he was the chief architect of both Microsoft Word and Excel.

Oh, and he went to outer space. Twice.

Yes, he’s accomplished a few things. Yes, this is a big deal.

“When I first joined Microsoft in February 1981 I was truly privileged to take part in the PC revolution, from just a glimmer of what was to come while I was at Xerox, and then at Microsoft creating the ecosystem leading to the universal acceptance of the mouse-based GUI interface and networking,” Mr. Simonyi writes on the Intentional Software website; Microsoft is purchasing the company he cofounded when he left the software giant in 2002. “For the last two years, we were working closely with Microsoft to see if there are synergies between our technology and Microsoft’s plans, which eventually led to today’s acquisition announcement.”

Why Microsoft purchased Intentional—getting Mr. Simonyi back in the process—is open to some speculation. But Microsoft executive vice president Rajesh Jha provides some clues.

“Intentional Software [is] a company that has been focused on creating a platform for a new generation of team productivity apps,” he writes in the Official Microsoft blog. “we continue to push ourselves to think about new ways to empower people … Intentional Software’s technology and talent will enhance our existing capabilities and strengthen our ability to add new tools and services to Microsoft’s robust productivity offering. We’re excited about the company’s work on productivity applications, especially given our focus of putting people at the center of experiences and our continued effort to reimagine collaboration.”

Mr. Simonyi also hints at what brought him back to Microsoft.

“One can imagine many new use scenarios that cut across devices,” he writes, noting how much interoperable pen- and touch-enabled devices, like Microsoft’s Surface lineup, have changed things. “In real life we have many desktops, and many other surfaces(!) such as whiteboards, bulletin boards, clipboards, and PC displays where data can be present or moved. The PC desktop should not, and need not, remain a limiting metaphor.”

Simonyi goes on to discuss group of people working together in various capacities, the many surfaces which we interact with that display data, and how “the surfaces on the new devices should show all kinds of data side-by-side and interwoven as a universal surface.” In the future, he says, we will interact with documents, not apps, using pointing, gestures, pens, touch, and voice, and machine learning will power the back-end.

Not surprisingly, perhaps, this is the type of work Mr. Simonyi has been doing since he left Microsoft. The Intentional Software website is now pretty bare, but it describes the company’s work as “reinventing productivity software” and “transforming how teams work in the modern workplace.”

“Intentional Software builds on the Intentional Programming project led by Charles Simonyi at Microsoft Research,” the site explains. “Our next generation application platform for team productivity is designed for the latest hardware technologies and the modern workplace.”

When I was coming up in the Microsoft world over 20 years ago, Charles Simonyi was well-established as a key player in the software giant’s early days, especially from the perspective of software development, given his creation of Hungarian notation. But he also created Microsoft’s application group, led the initial creation of Word and Excel (and Excel’s predecessor, Multiplan), and the Office suite of offerings, and was an early proponent of cross-platform code. Simonyi single-handedly introduced Microsoft to Object Oriented Programming (OOP) when he joined the firm.