That's pretty easy to do with just live rock. The trick is to add some diversity and still make it grow like that. I, too, have coraline algea growing like this, but I have many corals, fish and inverts. I notice that this person cleans the coraline off the front glass like I do.
Few people know that coraline algea does best with low light or no light at all. I notice that the tank has flourecents, and that's about it.