We (I'm on the xet team at HF) are open sourcing our spec + protocol in the coming months. So, with the spec and protocol open-sourced, anyone can create xet clients and implement the protocol to build a xet backend.

The specific implementation of our xet backend is deeply integrated into HF backend so open-sourcing it directly wouldn't be very helpful. Once we get the spec + protocol released it should be easy to generate a compatible backend.