I have to confess that I've always assumed that there is a difference to the way Mac writes and handles files - hence the need for a converter. Anything I do is done on a PC and I've noticed OS problems arising between Win98 and NT/2K, rare but sometimes compatibility issues are raised. As for sit/zip yes, either machine can open them, but surely there is some information added/stripped by the MacConverter program? Isn't it better to know that the file is purely Mac/PC based so that you know it needs to be fiddled with before it will work the way the author intended? Or am I way off base here?