The development of PDF began in 1991 when John Warnock wrote a paper for a project then code-named Camelot, in which he proposed … See more

A PDF file is often a combination of vector graphics, text, and bitmap graphics. The basic types of content in a PDF are:
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The basic design of how graphics are represented in PDF is very similar to that of PostScript, except for the use of transparency, which … See more

Anyone may create applications that can read and write PDF files without having to pay royalties to Adobe Systems; Adobe holds patents to PDF, but licenses them for royalty-free use … See more

A PDF file is organized using ASCII characters, except for certain elements that may have binary content. The file starts with a header containing a magic number (as a readable string) and the version of the format, for example %PDF-1.7. The format is a … See more

Logical structure and accessibility
A "tagged" PDF (see clause 14.8 in ISO 32000) includes document structure and semantics information to enable reliable text extraction and See more

Changes to content
In November 2019, researchers from Ruhr University Bochum and Hackmanit GmbH published attacks … See more