Microsoft announced the beginning of the technical preview program for Microsoft Office 15, the next generation of Microsoft Office.

The preview is the first time the company shares its work with a select group of customers, under non-disclosure agreements.

“These customers play a key role in our development process by testing early builds and providing feedback, which we incorporate into the final release,” says PJ Hough, CVP of Development on Microsoft’s Office Division.

“At this early point in our development cycle, I’m not able to share too much about Office 15, but I can tell you Office 15 is the most ambitious undertaking yet for the Office Division,” says Hough. “With Office 15, for the first time ever, we will simultaneously update our cloud services, servers, and mobile and PC clients for Office, Office 365, Exchange, SharePoint, Lync, Project, and Visio. Quite simply, Office 15 will help people work, collaborate, and communicate smarter and faster than ever before.”

The public beta will come this summer, the company says. At that point, more details about the release will be made public, obviously.

The current preview program is full, and closed to any additional participants.