Poppler is a PDF rendering library based on the xpdf-3.0 code base.
The package poppler-utils contains pdf utilities based on Poppler.
pdfunite: concatenate documents
pdfunite file1.pdf file2.pdf out.pdfpdfseparate: page extraction tool
extract from sample.pdf pages 3 to 5, generating sample-page-3.pdf, sample-page-4.pdf, sample-page-5.pdf
pdfseparate -f 3 -l 5 sample.pdf sample-page-%d.pdfpdftotext: text extraction
pdftoppm: convert to image formats
pdftoppm -png file.pdf > file.png
pdfinfo: document information
pdfsig: verify digital signatures