PDF toolsIn 1991, John Warnock, one of Adobe's co-founders, wrote an internal paper describing what he called the Camelot project. The problem it described is familiar to anyone who has ever opened a Word file on a different computer: documents looked different depending on the machine, the fonts installed and the printer. Warnock wanted a way to capture a document exactly as it was meant to look and show it identically anywhere.
Adobe already had part of the answer. PostScript, its page description language, could describe any printed page precisely, but it was a full programming language, heavy to interpret and awkward for viewing on screen. Camelot took the drawing model of PostScript and froze it into a simpler, structured file that a viewer could open quickly and jump around in. That file became the Portable Document Format.
1993: a slow start
PDF 1.0 and the first version of Acrobat appeared in 1993. Early on, the software to create PDFs was sold, and so was the reader. Few people paid for software just to read documents, and the format was not an obvious success.
Two decisions changed that. From version 2.0 in 1994, Adobe gave the reader away for free. And over the following years, organisations that needed to publish documents to the public, from government tax forms to manuals and academic papers, found that PDF solved their problem: one file, printable, identical everywhere.
Growing features
Each new version added capabilities: links and bookmarks, then forms, then encryption, transparency, embedded multimedia, 3D, layers. Version numbers went from 1.0 up to 1.7. The format grew from a static printout into something closer to a small application container, which is also why some PDFs today can do surprising things.
Specialised flavours
Different industries needed different guarantees, which led to standardised subsets. PDF/X, for reliable printing, was standardised from 2001. PDF/A, for long-term archiving, followed in 2005. PDF/E for engineering documents and PDF/UA for accessibility came later, in 2008 and 2012. We explain them in PDF/A, PDF/X and PDF/UA explained.
2008: handing it over
In 2007 Adobe announced it would hand the specification to a standards body, and in July 2008 PDF 1.7 was published as ISO 32000-1. From then on, PDF was an open international standard rather than one company's format. Adobe never published a "1.8"; the next version came from the ISO process.
PDF 2.0, ISO 32000-2, was published in 2017, with a revised edition in 2020. Since 2023 the PDF 2.0 specification can be downloaded at no cost, thanks to sponsorship arranged by the PDF Association.
Why it lasted
Plenty of formats from 1993 are gone. PDF survived because it does one thing that's genuinely hard: it fixes the appearance of a page. That's also its main weakness. A PDF is easy to read and print, and awkward to edit, which is exactly why tools like the ones on this site exist.