If PDF files are included using pdfTeX, PDF annotations are
stripped. The pax project offers a solution without altering
pdfTeX. A Java program (pax.jar) parses the PDF file that will
later be included. The program then writes the data of the
annotations into a file that can be read by TeX. The LaTeX
package pax extends the graphics package to support the scheme:
if a PDF file is included, the package looks for the file with
the annotation data, reads them and puts the annotations in the
right place.
