Nesbox also just submitted today with similar intents. Except it also allows sharing the GPU across multiple guests. https://news.ycombinator.com/item?id=49824884

Nesbox is just an underlying part of a broader (but early) kit to allow a system to stream multiple remote desktops at once. https://github.com/nestrilabs/nestri

Can this be used with proxmox?

Does it work under OpenStack?

Can this be used with a Windows guest?