This library is called pdf_paradise. Use the class ExtractPdfPage to extract .pdf pages from a larger .pdf file, by making use of ghostscript. Use class SetPdfTitle to set a new title for a .pdf (do note that we make use of the perl exiftools for this, for now). You can also use this project to merge .pdf files or shrink .pdf files. This functionality depends on gs (ghostscript). For more documentation, see the link to the right hand side called Documentation, on the rubygems homepage of this gem.