Is there any open-source remote desktop that forwards the full desktop experience (not just pixels, but also audio, input devices beyond keyboard & mouse, with high refresh rates and low latency)?
high refresh rates and low latency are non-trivial problems because they require realtime video encoding which is less bandwidth efficient than offline encoding which means you need a network transport which can shovel high bandwidth data at low latency and gracefully handle packet losses. if you do it over the open internet you also need to adapt to variable bandwidth. all these things have been done, but someone would still need to tie all of it together in an open source solution. There's the sunshine/moonlight combo for remote game streaming, but it lacks other features for remote desktop use.