Sony, Atlus, and Bandai Namco recently ended support for the online functionality in Demon’s Souls– which includes messages, co-op, invasions, and one boss locked behind online play- but that doesn’t mean the online is dead. The Souls community is really dedicated, and it looks like some of them may be looking at instituting private servers to keep the online alive.
As this Reddit thread discusses, an active work in progress is trying to add private servers so players still playing Demon’s Souls will be able to go online with it. The source code for this project has been released, so others can implement their own private servers, should they want to.
It will be hugely interesting to see what comes of this in the long run- usually, console games don’t get communities trying to keep their online functionality alive (Phantasy Star Online is one of the few exceptions I can think of), so this is a special case- hopefully, Demon’s Souls continues to live on.