PDF

History and Standardization of PDF - Adobe Systems released the PDF specification in 1993. - PDF was initially popular in desktop publishing workflows. - PDF competed with other formats such as DjVu, Envoy, and Common Ground Digital Paper. - PDF became an open standard in 2008 and was published by the International Organization for Standardization (ISO). - Adobe granted royalty-free rights for all patents necessary for PDF-compliant implementations. - PDF was standardized as ISO 32000 in 2008. - The latest edition, ISO 32000-2:2020, was published in December 2020. - ISO 32000-2 does not include any proprietary technologies as normative references. - The PDF Association made ISO 32000-2 available for free download in April 2023. - The specification is controlled by an ISO Committee of volunteer industry experts. Content of PDF Files - A PDF file can contain text, graphics, and images. - Content streams store typeset text. - Vector graphics are used for illustrations and designs. - Raster graphics are used for photographs and other images. - PDF files can also include multimedia objects, links, forms, and JavaScript. Technical Details of PDF - PDF is based on the PostScript page description programming language. - Fonts can be embedded or replaced in a PDF document. - PDF supports plug-ins for handling embedded content. - PDF documents can include forms and JavaScript. - PDF combines vector graphics, text, and bitmap graphics. Features of PDF - PDF supports encryption and digital signatures. - File attachments and metadata can be included in PDF files. - PDF allows for logical structuring elements and annotations. - Rich media, including video content, can be embedded in PDF. - PDF can handle three-dimensional objects using U3D or PRC. Miscellaneous - Adobe granted royalty-free rights for all patents necessary for PDF-compliant implementations. - The specification is controlled by an ISO Committee of volunteer industry experts.