Kmax version 1.x – 6.x is designed to operate under the original (classic) Macintosh OS.   KmaxNT runs under Windows NT/2000/XP  The file formats of these versions are not compatibile.  Kmax 7.x and above runs in the Java VM on specific versions of Windows, Mac OS X and Linux (Check the Kmax documentation to see which Kmax versions are compatible with particular OS versions).  The data and toolsheet formats for a specific version of Kmax ( > 7.x) are cross-platform compatibility.