Screen doesn't put the program in the background in the usual sense. It makes the program run in a virtual terminal, which you can still access normally. I use screen a lot so I can keep lots of terminal programs running, without being visible all at once. You can put screen itself in the background with all the programs running within, and open it later (perhaps when connecting from another machine).

I think this is its most essential feature. Many people learned to use screen around 2000 for using IRC; they could leave their IRC client running on some server, and return to their session the next day, without keeping their own computer on all the time.

For actually putting zanod in the background, I use the --no-console option. So
or to make it extra sure