/domains/Ylsrim/virtual
		 Virtual Rooms for the Ylsrim Domain

The Nightmare Object Library ships with a virtual desert to the east
of the main town of Ylsrim.  It is 25 rooms by 25 rooms in which
people can get lost.  What happens is when some objects references an
object in /domains/Ylsrim/virtual/desert/ but finds no file there, it
calls compile_object() in /domains/Ylsrim/virtual/server.c.  That
function returns an object which serves as the non-existent object.

The virtual server looks at the file name like:
/domains/Ylsrim/virtual/desert/15,12

That tells it to clone /domains/Ylsrim/virtual/desert.c and pass it
15, 12 as the argument to create().  Thus desert.c is able to set up
exits and such for its location at 15, 12 on the virtual desert grid.

You can thus write your own virtual grid, say for a forest, simply by
writing a forest.c like the desert.c given here.