PDF rendering library and command-line suite (pdftotext, pdfimages, pdftoppm, pdftocairo, pdftohtml, pdftops, pdfinfo, pdffonts, pdfdetach, pdfattach, pdfseparate, pdfunite, pdfsig) covering text/image extraction, page rendering, format conversion, metadata, attachments, and signature verification.
Command LinePDF viewer plus command-line tools (pdftotext, pdftops, pdftoppm, pdftopng, pdftohtml, pdfinfo, pdfimages, pdffonts, pdfdetach) for viewing PDFs and converting them to text, PostScript, image, or HTML, plus metadata, image, font, and attachment extraction.
Command LineCommand-line tool to merge, split, and rotate PDFs; fill forms with FDF/XFDF data and flatten them (or generate an FDF stencil); encrypt/decrypt with passwords; add watermarks/stamps; manage bookmarks, metadata, and attachments; repair damaged PDFs; and recompress page streams.
Command LinePostScript and PDF interpreter/renderer from Artifex: converts PostScript/PDF to images, text, DOCX, PCL, and XPS; compresses PDFs while preserving quality; converts to/validates PDF/A; adds an OCR text layer to scanned pages; imposition (N-up), ICC color management, and ZUGFeRD/Factur-X e-invoicing support.
Command LineLightweight C library, viewer, and CLI toolset for PDF, XPS, and e-book formats: renders and extracts text/images/metadata/structured content; creates, splits, merges, and compresses PDFs; adds annotations (highlights, stamps, shapes); permanently redacts content; digitally signs documents; converts between PDF, SVG, PNG, HTML, and PostScript; and embeds into web pages/apps.
Command LineGNOME's document viewer, built on Poppler for PDF (plus PostScript via Ghostscript, DjVu, DVI, multi-page TIFF, comic archives, and more): text/highlight annotations, text selection and copying (incl. from OCR'd scans), optional override of document print restrictions, integrated search, thumbnails, dual-page and full-screen/slideshow viewing. No form-filling support.