PDFjam is a small collection of shell scripts which provide a simple
interface to some of the functionality of the excellent pdfpages package
(by Andreas Matthias) for pdfLaTeX. At present the utilities available
are:
+ pdfnup, which allows PDF files to be "n-upped" in roughly the way
that psnup does for PostScript files.
+ pdfjoin, which concatenates the pages of multiple PDF files together
into a single file
+ pdf90, which rotates the pages of one or more PDF files through 90
degrees (anti-clockwise).
