Poppler

PDF rendering library and command-line suite — a fork of Xpdf that's become the de facto standard PDF engine underlying much of the open-source PDF ecosystem, powering tools like Evince, Okular, and countless downstream wrappers. Ships pdftotext, pdfimages, pdftoppm, pdftocairo, pdftohtml, pdftops, pdfinfo, pdffonts, pdfdetach, pdfattach, pdfseparate, pdfunite, and pdfsig, covering text/image extraction, page rendering, format conversion, metadata, attachments, and signature verification.