If you’ve seen my resume – or talked to me lately, you know that I create Acrobat plug-ins for a living. When people hear that, they usually think something like “Don’t forget to pick up the dry cleaning” or “I need to bring my cat to the vet for the rabies shot”… Yes, I understand, this may not be the most exciting topic, but probably only because you don’t know enough about what these “plug-ins” are, so let me explain.

 

Adobe Acrobat is a very powerful tool, more powerful that most users actually realize. I wont go into any details about how powerful exactly – at least not today. Lets just say that it has something for everybody. However, you may need something in addition to what Adobe provides, something that still is in the general area of PDF. Adobe may not have considered your needs because either the target market for “your” feature is too small, or to far out there… Or you are so far ahead of everybody else that they have not even thought about that feature yet.

Adobe did however do a very interesting thing: They created an interface that allows 3rd party developers to create solutions based on Adobe Acrobat – using plug-ins. It is a very powerful interface, and hence not something that you can pick up in an afternoon. There are several thousand pages of API documentation that one needs to understand before a plug-in should be written.

A plug-in is – from a technical point of view – a module or library that gets loaded dynamically at runtime. Acrobat will scan it’s plug-ins directory and will load any modules it finds. Once loaded, such a plug-in can extend Acrobat by e.g. adding menu items, toolbuttons, or event handlers (e.g. a function that gets executed whenever a documents gets loaded).

 

Interestingly enough, the plug-ins directory of a fresh Adobe Acrobat installation is not empty… A lot of Acrobat’s functionality is actually implemented as plug-ins. You can verify that on a Windows system by temporarily disabling all plug-ins by holding down the Shift key when bringing up Acrobat. That will load the application without any plug-ins. When you compare the toolbar or the menu bar with a fully loaded application, you’ll see what portion of the Acrobat core functionality is actually implemented in plug-ins.

The plug-in interface has different abstraction levels (COS, PDE, AV, …). If there is enough interest, I will provide information about how to navigate that API, and how to structure a plug-in.

The Acrobat SDK is available for free from Adobe’s Acrobat Development Center.

Here are a few examples of commercially available plug-ins that I’ve used:

• Enfocus PitStop Professional:
  This is a preflight tool.
• Quite Imposing Plus:
  The best PDF based imposition tool that I am aware of.
• Enfocus Browser:
  Allows to review and change the internal structure of a PDF file.

As promised, here are some PDF related tools that I don’t use, but either have used, have played with, or just know about how good they are. These are the tools that I recommend when somebody asks me “what would you use to do XYZ?”.

PrimoPDF

The best free PDF generator. Just see my previous blog post. If you need a PDF generator, download that program.

NitroPDF

From the friendly people who bring you PrimoPDF. This is a package that competes with Acrobat. It can edit PDFs, create forms, fill forms, create PDFs, … And it’s cheaper than Acrobat. There is a free eval version available. Download it, play with it and see if it covers all your PDF needs. If not, there is always Acrobat. An upcoming release will have OCR support (after release 6).

PDF Enhancer

The PDF Enhancer is a very powerful tool to “enhance” PDFs. Enhancement in this case can mean a lot of different things: Make them smaller, fix common PDF problems, embed fonts, add or modify color management information, … There are different versions available, even a server version. Apago also has a free eval version that you can download to see if it fits your needs.

Enfocus PitStop Professional

PitStop is a preflight tool that I used in my previous job. In addition to preflight capabilities, it also implements the Enfocus Certified PDF Workflow that allows a PDF file to contain an audit trail of all operations that were performed on it. In addition to PitStop Professional, Enfocus also offers the PitStop server, which can do anything Pitstop Professional can do in an automated fashion.

Quite Imposing Plus

This is simply the best imposition tool for PDFs. If you need to impose a PDF, Quite Imposing Plus can do it. It is not the easiest tool to work with. One of the best features of it is that you can create sample PDF files with page numbers to figure out how exactly an imposition scheme needs to be set up. Once you’ve figured that out, you can just re-run the same process again on your real document.

PDFLib

PDFLib is a great tool to programatically create PDF files. I’ve used an older version a few years ago. I’ve followed the development of the library over the years, and I still can recommend it as an alternative to iText.

What tools am I using to create/process/debug PDF documents? Here is list of my top tools and why I like them.

Adobe Acrobat Pro

Here are a few tasks that I use Acrobat for:

• Create

If you want the best quality PDF document, how can you go wrong with the Distiller from the people who invented PDF? There are many ways to create PDF files, but for high quality press work, I would not trust any other application.

• Edit and Process

Optimize, preflight, manage colors, insert pages, extract pages, remove pages, change page boxes, create interactive forms… Do I need to say more? Pretty much anything that’s possible with a PDF document can be done with Acrobat. Sure, there are other tools that can do some of these tasks as well, but there is no other tool that covers the broad range of features available in Acrobat.

• Debug

The preflight tool allows to check for syntax errors in PDF files, traverse the internal structure of PDF documents, look at fonts, …

• Programming

I also write software for Acrobat. That’s either done as a plug-in or as JavaScript, for demo purposes I occasionally also write sample VB programs that utilize Acrobat’s Inter-application Communication API.

Adobe Reader

Ghostscript

XPDF

iText

pdftk

It is a tool to do a number of things with PDF files (concatenate files, break a multi-page file into individual page documents, flatten forms, …). Take a look at the page that lits pdftk sample command lines to learn more about what is supported.

There is a small problem with pdftk: It’s no longer supported, and it cannot handle PDF files that use some of the newer PDF features. Also, there are (at least) two versions that are currently getting distributed: Get the newest one from http://www.pdfhacks.com/pdftk and not the one from AccessPDF. (Update: Both links now have the same version).

Mac OS X

Enfocus Browser

• An Acrobat plug-in


• A standalone application

My Favorite Acrobat 8 Feature

The Enfocus Browser is Back

One of the best features of the Browser is that it allows you to actually modify the PDF structure, however, you better hold back on that until you’ve read the PDF spec a couple of times. It’s very easy to break a PDF file by making just a few changes.

One of the biggest advantages of the standalone version is that I can look at a PDF file that may not open in Acrobat and find out why.

There are a number of other applications that I don’t user personally, but that I do recommend to others because I know how good these apps are. More about that in a future post.