Short answer: Maconverter became obsolete when P5 came out. Longer answer: Prior to P5, Curious Labs had separate, somewhat incompatible file formats between the Mac and Windows versions of Poser (because CL did something Mac-specific with those file formats Apple told developers NEVER to do). MartinC wrote Maconverter as a Mac utility to convert Poser files back and forth between Mac and PC formats (for technical reasons this cannot be done in Windows). When P5 came out the file formats were standardized on a simpler model with no OS-specific features and no need for conversion. [this ought to be a FAQ item]