Apple OS/X Hex Editor

If you need a hex editor in OS/X to see exactly what is in a file, download this free one. 
 http://ridiculousfish.com/hexfiend/ 
 Two other Unix commands for working with binary data are dd and od . You can read about them from their man pages: 
 
 man dd 	 man od 
 
 Taken from email by Jose Hales-Garcia to OS/X Forum List