Comment by tabbott

I'm sure you could do some of Zulip's features on top of Matrix.

But for what it's worth, as Zulip's lead developer, every time I'm looked at whether we could have built Zulip on top of Matrix, it just feels impossible to me. And a big part of it is the architectural decisions Matrix made to support a decentralized E2EE social network, which are not required for a self-contained chat system like Zulip or Slack (which can still be bridged with other chat systems). Permissions enforcement, performance, and lots of other details really benefit from the more focused goal, where we've explicitly decided we're not building a generic distributed network architecture and are not competing with WhatsApp.

That said, I think it's great that we have multiple OSS chat systems with different strategies that are targeting different collections of niches!

I will never understand why so many organizations entrusted the communications fabric of their organization to Microsoft and SalesForce Cloud services over the last decade. If an organization can succeed in escaping Teams or Slack to Element/Matrix, that's great, even if it's a use case where Zulip would be a better end-user experience for their requirements.