The software referenced in this article is either Free or Open Source software and should be available to, at a minimum, both Microsoft Windows and GNU/Linux operating systems. In Linux, I recommend installing software through your package manager, unless you need the latest and greatest. Most of my information can be found in and was retrieved from Wikipedia.
The PDF Format, its subsets and the Ghostscript software
The PDF format was created by Adobe in 1993 and has become as ubiquitous in academics and business alike as Microsoft Word’s .doc format. It is the native file format of the Adobe Acrobat family of products, which goal it is "to enable users to exchange and view electronic documents easily and reliably, independently of the environment in which they were created." (Adobe Systems Inc., PDF Reference 1.7) However, unlike Microsoft and its proprietary formats, Adobe decided to open its format in 2008 as the ISO 32000-1:2008 open standard, with its range of subsets; thereby allowing anyone to create applications that can read and write PDF files without having to pay royalties. It should be noted that Adobe still holds patents over the file format, though developing software according to the PDF specification is royalty free. To wit, having PDF as an ISO standard means that the openness of the standard is as good as protected by law.
The main advantage to you and me with regards to PDF documents is that we can use them between us without having to worry about what software to use in order to do so. I think we can argue that making PDF an ISO standard was the only way Adobe could ensure its document format’s future, as will become more visible in time, with the Open Document format that is an ISO standard challenging Microsofts’ proprietary .doc and .docx document formats. But enough chit-chat!
The different subsets of PDF format are:
- PDF/X a.k.a. "PDF for the Graphic technology" or Prepress digital data exchange
- PDF/A a.k.a. "PDF for Archive" or document format for long-term preservation
- PDF/E a.k.a. "PDF for Engineering" or Engineering document format using PDF
- PDF/VT a.k.a "PDF for variable data and transactional printing"
- PDF/UA a.k.a. "PDF for Universal Access" or document file format enhancement for accessibility
.. but most of us will be using the fully-featured PDF v 1.7 or just Portable document format.
The Ghostscript software suit originally created by L. Peter Deutsch in 1986, has become the de facto standard raster image processor and engine behind PostScript and PDF viewers that are not released by Adobe. If you have tried PDF related software that was not made by Adobe then chances are you are using some variant of Ghostscript, preferably GNU or GPL Ghostscript. Most of the software in this post will be using some part of Ghostscript.
Unlike document formats such as .doc or .odt, the common use of PDF files is as a way to display the same information in the same manner on several different systems, that is, just like printed text; without changes made to it. This has caused a split between software that read and software that writes PDF files. Here are some examples of both, and then some utilities I’ve come across.
If you are a Windows user, then chances are you are running Adobe PDF reader which is a slow and virus vulnerable beast, eating up your CPU cycles while you wait for the document to be displayed (or your patience to die).
If you need a program that display PDF files and little else, try Evince. It’s a multi-platform, small and extremely fast document reader for PDF, PostScript, DjVu, TIFF and DVI file formats that supports searching, thumbnails and indexing among other things. It’s licensed under GNU GPL v2.
I have previously recommended Foxit Reader for being fast, but it has gotten bloated over the years and has a cartoonish layout. In addition, it tries to install a toolbar, and no me gusta toolbars. To find other recommended readers for Microsoft Windows, GNU/Linux or Apple Mac OS, see PDFReaders.org by the Free Software Foundation!
PDF Editors (writers)
When you enter the world of PDF editors and related software, you’re diving head first into the domain of desktop publishing, font faces, and all those arcane and magical things that seem to require a long academic background or at least a semester at Hogwarts to understand. For some reason, publication departments and type setters all over the world are obsessing over how important and difficult their jobs are. At least I’ve met that attitude more than once. As if they’re trying to scare people away from a simpler life. Don’t worry, we don’t want your jobs, practical experience and technical knowledge. Just your software.
This is Scribus, which "brings professional page layout to Linux/UNIX, Mac OS X and Windows desktops with a combination of press-ready output and new approaches to page design." I haven’t used Scribus more than once, when I just wanted some quick editing done. But the people over at Libre Graphics Magazine certainly have and know how to use it! And if you download issue 1 in high graphics (PDF, 60MB) I think you will see that desktop publishing is in no need whatsoever of proprietary software. Congratulations! Consider a donation or subscribing.
But for mortals such as myself, merely importing and editing PDF files are usually what I need to get the job done. For that you can use LibreOffice Draw, the GIMP or Inkscape. Granted, none of these were made solely for PDF editing, and the last one can only do 1 page at the time, but they can all do aspects of it. To truly work with PDF however, I guess desktop publising with Scribus is your best bet. And if you simply want to save your regular document as a PDF file, see the utilities section below or simply use the export function in LibreOffice.
For instance, saving presentations in PDF format with the setting of opening in full screen provides a fail-safe solution for those pesky conference computers that may or may not render your graphics the right way depending on what software they have installed. Chances are they at least have a PDF reader. So if you create the presentation in LibreOffice Impress and select Export as PDF.., choose PDF/A under General and Open in full screen mode under User Interface you only need a PDF reader to get the job done. What other tools might come in handy?
Some PDF utilities I use
Most if not all of these utilities use the Ghostscript suit mentioned above. If you have to install and configure Ghostscript separately in order to get the desired utility working, I recommend GNU Ghostscript which has a Free software license.
Besides my PDF reader, I probably use PDFCreator the most. It acts as a virtual printer in Windows, so sending any file to it will return a "virtual print-out" in PDF format. PDFCreator allows you to specify PDF/A format or enter a password. PDF password protection must not be taken as real protection since it is easily circumvented, but it may be practical as a deterrent from editing the file by mistake. But remember to consider future accessibility.
It is very important that during the installation you decline to install the PDFForge toolbar, which has a rocky security record. As long as you refrain from installing the toolbar PDFCreator itself will work like a charm, and you’ll stay safe. Alternatively, you can skip PDFForge entirely and install its individual parts yourself by following these step-by-step instructions: Creating a free PDFWriter using Ghostscript.
PDFCreator is not available in GNU/Linux, but we always have the option of piping a file through the Ghostscript software suit in a terminal. As stated before, all you’ll ever need is Ghostscript. Read more here: How to use Ghostscript
Users have also come asking how they could merge PDF files without having to open them all up, cut & paste or purchase expensive Adobe software. A small tool that also uses Ghostscript does just this, and it’s called PDF Blender. You’ll have to download Ghostscript’s win32 binary first, preferably the GNU Ghostscript version, and then having installed PDF Blender point its "Path to gswin32c.exe" bar in File-Preferences to the full path of gswin32c.exe. I just put it in C:Program Filesgsbingswin32c.exe
PDF Blender allows you to specify as many input files you want, order them, change document security, and of course, merge them all into one. A small additional note: If you select English during install, instead of default, you may end up with the "Nerdy edition" which may be a bit confusing to users that are not nerdy at all. Just go File-Select Languages.
Lastly, I just wanted to add GSView and PDF Toolkit Builder which provide you with the remaining features of the Ghostscript software suit in command line as well as graphical user interface. I haven’t had the opportunity or the need to try them out, but they certainly look versatile.
As you’ve come to understand, the story of the PDF format and the Ghostscript software suit is a story of free or open source software and open standards. With the existence of GNU GPL’ed software such as GNU Ghostscript comes the creation of a heap of other software that is free for us to use and evolve, all embracing the open ISO standard that — despite all its patents in the world — Adobe cannot take away from you, me or the future. I think Adobe did a very smart move.