The Fluid Project uses the Matrix communication protocol for collaborative discussions.
Recommended Client
Element is the default client for accessing Matrix and provides desktop, mobile, and web apps.
Occasionally the Element desktop app can get stuck trying to send or receive a message. We've found that if you run into these kinds of issues, opening Settings, selecting "Help & About", and clicking the button that says "Clear cache and reload" under the "Advanced" section may resolve the problem.
Other Clients
See "Clients | Matrix.org" for a list of other clients