PDF File Format

Adobe's Portable Document Format (PDF) file format was developed from their experience of Postscript (PS) format, and was designed to allow users of disparate software applications to share their document across a variety of hardware platforms and systems, without losing the format and structure of the original document.

PDF has become a defacto standard and Adobe permit PDF readers to be developed by third parties. As a result PDF usage continues to expand.

PDFs are designed to deliver the document in the same visual layout as the original document, including any graphics, fonts, photographic images etc. PDFs can contain many hundreds of pages within single file, and can contain hyperlinks to other pages within the document, or to HTML pages on the web.

Adobe's Acrobat software was the first to allow the creation of PDF files, although this facility has been extended to a wide range of different applications through the addition of a PDF-writing plug-in or driver. To view the finished PDFs however, users can use the Acrobat Reader software (which was originally charged for, but which is now free). Acrobat Reader needed to be installed on the user's machine before viewing could occur. Nowadays, users can view PDFs within their web-browser through the Acrobat plug-in file or ViewONE Pro amongst other viewers.

Adobe professional markup tools can be used to add annotations or markups to PDFs. These tools will change the PDF files (annotations and markups are stored within a PDF file) and are licensed on a per user based. Daeja provides an alternative mechanism which allows annotation without having to change the original PDF and is licensed per server.

Daeja's PDF Module for ViewONE Pro allows users to view and annotate PDFs inside ViewONE Pro without the need to have separate browser plug-ins or thick client applications installed. ViewONE Pro's Annotations Module is also licensed by the server rather than the user meaning that there's no per-user licensing, to minimize costs.