Microsoft this week unveiled Project Lively, an Office add-in that can automatically refresh files when other people update them. It’s the latest thing to come out of Microsoft Garage, an operation that develops experimental apps for Android, iOS, and other platforms.

It’s notable because it introduces sensible modern functionality — almost like Office’s real-time co-authoring, except it doesn’t have to be in real time, and, more interestingly, it doesn’t rely on a traditional file-sharing service like Microsoft’s OneDrive.

Once you’ve installed the Project Lively add-in on your PC and enabled it in Word (Word 2016 for Mac and Windows and Word Online support it), you can choose to automatically have a given file refresh with other people’s changes, and you can also elect to automatically save your changes periodically.

What’s actually happening is that Microsoft is saving an encrypted copy of your file in its Azure public cloud — even though you have actually saved your original file on your PC and then shared the file with your friend, who has saved it to their PC.

Here’s an example to show how the system works:

Jane creates a new file. She types out a couple of paragraphs and then saves it the regular way, using File > Save. Then she adds a paragraph to the end of the document. Then, after setting up Project Lively, she hits the Save button inside the add-in windows.

At that point, she wants to share it with her colleague Karina. So Jane composes an email to Karina, attaches the file the usual way, and hits send. Ordinarily the file would be static, but with Project Lively, it won’t be.

Karina opens the file and installs Project Lively and turns it on for the file from Word’s Home ribbon.

Because Jane had made some changes after saving the file in the traditional way — and then saved those changes with Project Lively on her PC — Project Lively on Karina’s PC will inform Karina that updates are available.

Karina hits the yes button, indicating that she would like Project Lively to refresh the document automatically with the newest changes, without asking each time. Like magic, the newest paragraph shows up at the bottom of the document.

Sure enough, when Jane adds another paragraph at the end of the document and hits Lively’s save button, those changes will show up immediately on Karina’s PC.

This might sound complicated, but it’s actually quite cool. Microsoft thinks Project Lively could be useful for those times when you send your document but then realize that you’ve forgotten to make some important changes. With Lively you can go back and make those changes, and when your colleague checks the document, the changes will be there.

A few Microsoft employees developed Project Lively at a hackathon last year.

“We wanted an easy way for users to collaborate without a lot of extra complexity,” the team — Rorke Haining, Sriram Iyer, Bryan Jeffries, Lawrence Landauer, and Mike Paer — wrote in a description of the software. “During the hackathon, we were able to create a simple Office add-in that accomplished our goal; however, we want to release as a Garage project to gather more feedback that will hopefully shape some of the sharing and collaboration features in Office.”

You can find the add-in on the Office Store here.