Fluid is a free and open source computer platform for real-time collaboration across applications.

Microsoft first demonstrated the software at its Build conference in May 2019[1] as a framework that would allow for real-time collaboration between users of its Office on the web online office suite.

It replaces the concept of a "document" with a cloud address for real-time collaboration and sharing of content forms including text and tables.

It is designed for integration with other services, such as live translation and Cortana voice assistance.

[2] Public and private previews of the software began in November 2019.