https://techcrunch.com/2020/05/19/microsofts-fluid-framework-is-now-open-source-comes-to-office-365/

Fluid Framework was one of the sleeper hits of Microsoft’s 2019 Build developer conference. The idea behind the Fluid Framework is to provide developers with a new platform for building low-latency collaborative experiences around documents — and Microsoft itself is using it to do just that by rethinking some of the workflows in its own Office applications.

Now, for the first time, it is building Fluid Framework into a couple of key productivity apps, starting with Outlook and Office.com. In addition, Microsoft is also open-sourcing the Fluid Framework and making the code available on GitHub within the next few weeks.