I use Macromedia FreeHand© , one of the two illustration software packages most often used by design professionals (the other is Adobe Illustrator©). I am using the Windows version of FreeHand for the PC.
FreeHand drawings may be exported to several different graphic formats to use in a wide variety of situations, including Adobe Illustrator, Encapsulated PostScript, PDF, Windows Metafiles, and all of the bitmap type formats (*.bmp, *.tif, *.gif, and *.jpg, the latter two most commonly used for Web sites).
If you are working with a professional publisher or book designer, in some cases the publisher may be able to use the FreeHand file directly. But I will provide the map or other graphic to you or your publisher in whatever format is required, or in multiple formats.
In addition to what I provide your publisher (often simply as an attachment to email), I will provide you with a disk with the FreeHand version and whatever other formats you desire for your own future use. You or another person may edit the map in FreeHand or Illustrator for another purpose. Note that once your map is published, you may need to seek permission of the publisher to use the map in other publications, even in modified form.