I have been working on this project for a while now. This is Crowbar - a multiprotocol old messenger server written in NodeJS. It’s killer-feature - full interoperability between all supported protocols.
We’re aiming to implement the following protocols:
The project is still in early development, but we plan to release it before 2027. It will be fully open-source and modular (meaning that anyone will be able to develop their own protocol implementation and integrate it with the other ones without any trouble).