I remember a time where the general effort was to have a common protocol and a number of inter-operable clients for chatting on the desktop. (XMPP?, not sure)

I remember a time where the general effort was to have a common protocol and a number of inter-operable clients for chatting on the desktop. (XMPP?, not sure) I wonder if its possible to have a common messenger format and a series of independent servers and providers that can service a variety of users, while allowing users to switch servers / providers. Monetization will always happen, at-least we dont have to be worried about central control / censorship.