I am using Microsoft office 2004 with excel verson 11.3.5 on my mac running os 10.6.8 and want to move to the new os Maverick. I believe that my version of excel will not work on Snow Leopard and probably not Maverick. I will consider buying a newer version of excel or switching to the apple spreadsheet program. My concern is that my current excel spreadsheets will not port over to the newer software/operating system.