Xpdf is a viewer for Portable Document Format files. The Xpdf project also includes a PDF text extractor, PDF-to-PostScript converter, and various other utilities. It runs under the X Window System on UNIX, VMS, and OS/
Xpdf is an open source PDF viewer for the X Window System and Motif. Xpdf runs on practically any Unix-like operating system. Xpdf can decode LZW and read encrypted PDFs.