[ Tuesday, 13 November 2007, axio ]
PDF documents are at present the most popular form of distributing documents throughout the Internet and a presentation tool at the same time. They owe their popularity not only to well defined standard embracing text, pictures and hyperlinks, but foremost to the fact that once created they can be read under nearly every operating system and its underlying platform. Of course, to open a PDF document one has to have an appropriate application.
Author: Karol Kozioł
PDF (Portable Document Format) – universal format for electronic documents. Its specification embraces PDF file creation, distribution, and printing. The format was designed by Adobe Systems in 1993 and was based on the PostScript language. The newest version is 1.7. Adobe decided to open the PDF format in 2007 and submitted it to the ISO organization for standardization.
Not only Acrobat Reader!
There are quite a few PDF readers (called PDF viewers as well), albeit the first, proprietary, and so called “official” PDF viewer is Acrobat Reader from Adobe Systems Inc. The company is also the father of the PDF format. The mere fact that the Acrobat Reader was an application with a closed source code didn’t appeal to many GNU/Linux admirers, and consequently led to the creation of multiple open-source alternatives. Viva l’difference! In this text I will describe the following readers: Acrobat Reader, Xpdf, KPDF, Evince, ePDFview and Okular.
What to expect from a PDF viewer?
Well, first of all any PDF reader should show the PDF contents correctly. A trivial statement but there are a lot of different documents in circulation — administration documents, presentations, science theses, e-books, magazines, leaflets, newsletters, line arts for coloring for children, etc. and good rendering is a must for these kinds of viewers. In other words they should have the ability to display contents in many view modes.
It would be appreciated, too, if a PDF reader was able to remember the last viewed page — a very useful and helpful function when reading an e-book or a longer document.
PDF Readers — the comparison
The author paid attention to applications’ responsiveness or how fast they were running. He also looked into the number of configuration options, and ergonomics of the viewers. The results were put together in a table followed by short descriptions of each package.
|Licencing terms||Proprietary||Open Source||Open Source||Open Source||Open Source|
|Relative start up speed||low||high||medium
|Side panel with thumbnails||yes||no||yes||yes||no|
|Double page mode||yes||no||yes||yes||no|
|Full screen mode||yes||yes (under right mouse button)||yes||yes||yes|
|Fit page/width scaling||yes||yes (in the zoom selection box at the bottom)||yes||yes||yes|
|Viewing ergonomics (space button scrolling,
mouse scrolling, arrows clicking)
|Mark and Copy functions||yes||very basic||yes||some||no|
|Remembering last page viewed||yes, but not activated by default||no||yes||yes||no|
|Configuration options||a lot||none||a few||none||very little|
PDF Readers — short summary
This is my short summary of the PDF tested viewers, the purpose of which is to present the essential features of the selected apps, the ones that make them different from the rest. I tried to be as objective as possible.
Adobe Acrobat Reader
Professional, popular and highly advanced PDF reader. It offers a lot of options and it is easy to use in different view modes. Cons: it doesn’t remember last viewed page and starts slowly. Pros: it seems to me it renders big documents faster than other viewers based on xpdf engine (tested on A0 paper size). Adobe company gives away plug-ins for the most popular web browsers.
Excellent old-fasioned reader written for X Window System. It shows the simplest and spartan GUI, but it’s very fast. Next generation PDF engines are based on XPDF — among them, Poppler, which laid the foundations for such readers as KPDF, Evince, and ePDFview.
PDF viewer for KDE graphical environment. I must admit it is my favorite reader. It makes it possible to insert bookmarks into browsed documents. That way a reader (this time a person) can insert a few bookmarks into a multipage document and gain quick access to selected information without resorting to manual scrolling of the document page after page. Thanks to KParts technology, it can be integrated into the Konqueror web browser.
Known formerly as Gpdf. This application is part of the GNOME desktop. It can read not only PDF files, but PS, TIFF, ODF, DVI, and DjVu files as well. Putting it simply, it is a very versatile viewer of electronic documents, but not as advanced as Kpdf (yet).
ePDFview — fast and easy reader
This is a simple and very fast application but devoid of many handy functions. It’s still in the development cycle, but let’s hope it will evolve into a full fledged PDF viewer without losing its responsiveness.
GhostScript and its front-ends
Ghostscript is a free Postscript language interpreter. Its corresponding viewer known to the world as Gv (gv) is able to view both PS and PDF files. So it is one step ahead of Xpdf, which can only read the latter. Other popular PS biewers areGhostView, and KGhostView.
This application is still considered unstable but it should be ready with KDE 4.0 which is scheduled for release in January 2008. Similar to Evince, it will be able to service such document types as PDF, PS, DVI, DjVu, TIFF, ODF, CHM, and graphics files.
This text is based on the article published in Dragonia Magazine, a Polish online magazine about Free and Open-Source Software. You can download the latest Dragonia issue (first one in English from our mirror). The article has been slightly modified compared with the original version by the PolishLinux team.
Translated by P2O2, Proof-read by Jake Conley