PDF Readers
The Adobe Portable Document Format (PDF) is a popular (if strongly criticized) document format standard. One problem is the bald assertion of many sites providing material in PDF that "you must use Adobe Acrobat Reader" to access the material. This is simply untrue (however popular a misconception it might be — Google shows over 30,300 results for this term).
There are several applications you can use other than Adobe's own proprietary products for PDFs, including. This is meant to be a list of such alternatives.
Notes:
- URLs: for most GNU/Linux distributions, many of these tools are pre-installed or are installable via your distribution's packaging system. Try these first, using the URL source as a last resort.
- Platforms are: GL = GNU/Linux, B = *BSD, U = Unix, LW = legacy MS Windows, LWX = legacy MS Windows with an X server (e.g.: Cygwin X), OSX = Macintosh OS X.
- GUI: Does the application offer a GUI interface.
- Console: Does the application offer a console / text-only interface and output. Note that this may offer limited functionality, particularly for graphical or scanned-in PDF files (e.g.: fax TIFF images in PDF wrappers).
- Free Software: Licensed under terms recognized as FSF Free Software or OSI Open Source licenses.
- Notes: Additional information. Unless noted, all applications do offer text search, hyperlinks, thumbnail contents, and passord-protected PDFs.
The usual "old reliables" are xpdf and gv, though users of GNOME or KDE might prefer the project-oriented PDF viewers.
Readers
| Program | Platform | GUI | Console (text-only) | Free Software | Notes |
| Ghostscript, ghostview, GSview | GL, B, U, LW | Yes | No | Yes/No (GPL and AFPL) | These are an interpreter and two viewers. Specifically supporting legacy MS Windows in native versions. |
| Gpdf | GL, B, U | Yes | No | Yes | GNOME Project PDF viewer, based on xpdf. |
| gv | GL, B, U | Yes | No | Yes | Ghostscript-based viewer. Far better paging than most of the PDF-specific viewers, but lacks search, hyperlink, and thumbnail features. Based on Ghostview. |
| KPdf | GL, B, U | Yes | No | Yes | KDE Project PDF viewer, based on xpdf. |
| pdftotext | GL, B, U, LW | No | Yes | Yes | Properly, a spin-off of the xpdf project, part of xpdf-tools in Debian GNU/Linux. Full text search (through your pager), no hypertext or thumbnails. |
| ViewPDF | GL, B, U, LWX | Yes | No | Yes | A PDF viewer for GNUstep. Controls and operation are awkward. |
| xpdf | GL, B, U, LWX | Yes | No | Yes | An open source GUI viewer for Portable Document Format (PDF) files. |
As for why you'd care for one of the above alternatives to Adobe's own offerings, there are two general reasons:
- The free versions tend to be more up-to-date, bug-free, and better fits for specific environments (CLI, KDE, GNOME, WindowMaker / GNUstep) than Adobe's ancient Motif-based interface.
- Remember Dmitry!. Adobe is the company which jailed and persecuted a programmer for nearly a year, before dropping all charges, largely for providing solid evidence of the poor quality of Adobe's own encryption solutions. Of course, DRM = digital restrictions management is a whole 'nuther ball of worms.
[RM comments: It's worth also reading LWN.net's 2004-11 "Grumpy Editor's Guide to PDF Viewers", http://lwn.net/Articles/113094/, which updates the above somewhat, and adds coverage of ggv = GNOME Ghostview (not the same as Gpdf), kghostview (not the same as KPdf), and the aforementioned Adobe Acrobat Reader = Acroread.]