PDFTK Builder - PDFTK Builder is a free graphical interface to for PDFTK, making it much easier to use.
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.
QPDF - QPDF is a command-line program that does structural, content-preserving transformations on PDF...
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
PyPDF2 - PyPDF2 - A utility to read and write pdfs with Python
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request