MacUser:"This XTension is no longer required for QuarkXPress 6."
Don't know where you got that info.
OS/PLATFORM: Mac
SIZE: 544.54 Kb
SEE: Creo PXT 4.0 Release Notes
QuarkXPress® 6.1 XTension used to make PostScript® and EPS files for use with Preps and TrapWise. Works only with QuarkXPress 6.1 on Mac OS® X 10.3. Includes the PXT User Guide. June 1, 2004
Creo PXT 4.0 (.zip format)
OS/PLATFORM: Windows
SIZE: 410.63 Kb
SEE: Creo PXT 4.0 Release Notes
QuarkXPress® 6.1 XTension used to make PostScript® and EPS files for use with Preps and TrapWise. Works only with QuarkXPress 6.1 on Windows® 2000 and Windows XP®. Includes the PXT User Guide.
From Creo's Website Trapwise downloads section.