Also, what does "Nowhere in 'docker run -i -t ubuntu /bin/bash' does it say something about LXC." even mean?
Docker is built upon LXC features. It needs them to work. LXC not there? It's not gonna work.
I think that the parent was trying to say that the docker interface is not specific to LXC, only the backend implementation is, so there is "nothing" preventing the backend from supporting other kernels that have the requisite features.
That said, the containers would be OS-specific by definition.
Who will run MacOSX in server farms anyway? If you're using Windows already, why not spend more for some fancy virtualization or container like products, say from VMWare?
Mono is more like a different implementation of interesting languages. If you like C#, you can use mono to write and run on Linux. If you want to write Windows programs, you won't use mono.
https://medium.com/boot2docker-lightweight-linux-for-docker/...