Current Release provide you methods to convert PDF to Images as well as Images to PDF, future releases will included more functions to interact with PDF files
http://www.pdflib.com/download/free-software/pdflib-lite-7/
llPDFLib is a pure Object Pascal library to create PDF documents
PdfLib CORE is a fast PDF editing and reading library for modern .NET Core applications.
MuPDF based PDF rendering library.
Binary Python bindings for poppler utils for content extraction
PDFlib object-oriented PHP wrapper
This is a ffi wrapper for pdflib (http://pdflib.com) for use with node.js.