> How many Matrix servers are out there ? One, that is still in beta (Synapse).
Worth noting that Matrix as a protocol and Synapse as a server implementation left beta in June 2019 (https://matrix.org/blog/2019/06/11/introducing-matrix-1-0-an...). Matrix is deployed by governments and civic institutions the world over including emergency services. It is literally trusted in life or death situations.
Thanks Neil. It's difficult to find alternative servers on that page so I will help by linking to The Construct which is the only other federating server. Though it is not yet stable, it is the only functioning third-party server and has more progress than your own reference implementation's rewrite!
Check out https://github.com/matrix-construct/construct and join us at #admins:matrix.org