Arbortext Software Compatibility Matrix for 5.3.
http://www.ptc.com/appserver/wcms/standards/fileothumbredirect.jsp?im_dbkey=46355&icg_dbkey=522 (You'll need to log in.)
How to find this doc:
http://www.ptc.com/support/arbortext
Right Hand Nav: "Reference Documents"
Set Product to "Arbortext Editor"
Set Release to "5.3"
Set Document Type to "Matricies - Software"
Cheers,
Liz