As Mac OS X Mavericks (10.9) has not been officially released by Apple, so the initially launched version of QuarkXPress 10 will not work on Mac OS X Mavericks (10.9) or any other pre-released operating systems. QuarkXPress 10 will support OS X Mavericks (10.9) within 90 days only after its official release by Apple. For more information please visit: http://forums.quark.com/p/32841/121957.aspx#121957