The world map is in the process of being expanded. The map set formerly know as "big-world" is now the default and only supported map set. Going forward (25-January-2005) it is referred to as crossfire-maps.
Info & README
World Map - Image
Download World Map
Use the following SVN Checkout command:
(Careful of line wrap, command should be all on one line..)
svn co https://svn.code.sf.net/p/crossfire/code/maps/trunk
See the SVN page for more details on using SVN