The cpdf command line tool allows you to manipulate existing PDF files in a variety of ways. For example: * Merge PDF files together, or split them apart * Encrypt and decrypt * Scale, crop and rotate pages * Read and set document info and metadata * Copy, add or remove bookmarks * Put multiple pages on one (imposition) * Stamp logos, text, dates, page numbers * Add or remove attachments * Losslessly compress PDF files * Convert PDF files to and from JSON This tool has been available commercially from Coherent Graphics Ltd since 2007, in 2013 it was released for free under a not-for-commercial-use license. This script builds the cpdf command line tool and cpdf as an OCaml library.