What is Portable Document Format (PDF)?
PDF was developed in the early 1990s as a way to share documents, including text formatting and inline images, among computer users of disparate platforms who may not have access to mutually-compatible application software.
In those early years before the rise of the World Wide Web and HTML documents, PDF was popular mainly in desktop publishing workflows.
Portable Document Format (PDF) is a file format used to present documents in a manner independent of application software, hardware, and operating systems.
Each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, graphics, and other information needed to display it.
In 1991, Adobe Systems co-founder John Warnock outlined a system called "Camelot" that evolved into PDF.
While Adobe Systems made the PDF specification available free of charge in 1993, PDF was a proprietary format, controlled by Adobe, until it was officially released as an open standard on July 1, 2008, and published by the International Organization for Standardization at which time control of the specification passed to an ISO Committee of volunteer industry experts.
In 2008, Adobe published a Public Patent License granting royalty-free rights for all patents owned by Adobe that are necessary to make, use, sell and distribute PDF compliant implementations.
However, there are still some proprietary technologies with published specification defined only by Adobe.
From version 2.0 onwards Adobe distributed its Adobe Reader program free of charge, and continued supporting the original PDF, which eventually became the de facto standard for fixed-format electronic documents.
Get a free reader http://get.adobe.com/uk/reader/