I have been using FaxSTF for well over 5 years including MacOS 9, MacOSX Jaguar, and MacOSX Panther. I have had no problems using FaxSTF to support my personal and business requirements during this time. It has just worked for me. I have not upgraded to the latest version because what I have works just fine and I have not needed the new features. The fax capability that Panther has works but is not "manage" faxes as well as FaxSTF.