There is only one file type that uses the .P65 extension:
PageMaker 6.5 Document
A P65 file is a document created with Adobe PageMaker 6.5, a program used by businesses and home office professionals to create page layouts. It contains formatted document text and images. P65 files are typically used for brochures, cards, newsletters, and other professional publications.
NOTE: P65 files can be opened by PageMaker 6.5 or 7.0. They can also be opened by Adobe InDesign (CS6 or earlier), which has replaced PageMaker.
|Adobe InDesign (CS6 or earlier)|
Updated: October 1, 2017