The Portable Document Format (PDF) specification, as released by the International Organization for Standardization (ISO) in the form of a series of related standards (ISO-32000-1 and -2, ISO-19005-1, -2, and -3, ISO-14289-1,...), was originally created by Adobe Systems Inc.
Carousel was the original code name for what later became Acrobat. The name Carousel was already taken by Kodak, so a marketing consultant was asked for an alternative name. These were the names that were proposed:
- Adobe Traverse - didn't make it,
- Adobe Express - sounded nice, but there was already that thing called Quark Express,
- Adobe Gates - was never an option, because there was already somebody with that name at another company,
- Adobe Rosetta - couldn't be used, because there was an existing company that went by that name.
- Adobe Acrobat - was a name not many people liked, but it was chosen anyway.
Although Acrobat exists for more than 20 years now, the name Carousel is still used to refer to the way a PDF file is composed, and that's what the first part of this book is about.
In this first part, we'll:
- Take a look at the basic PDF objects,
- Find out how these objects are organized inside a file, and
- Learn how to read a file by navigating from object to object.
After reading this part, you'll know how PDF is structured and you'll understand what you see when opening a PDF in a text editor instead of inside a PDF viewer.