PD is a powerful PDF Inspector. PD shows objects tree of PDF Document and list of XREF tables. You can search for any specific object by ID, type or data.
All References to or from any particular object can be displayed. Each object or stream can be saved to external file, images exported as regular image or as PDF stream. Syntax of page contents is highlighted, each command has a description.
512 MB RAM, 32 MB free disk space