I was there for the whole thing. It was the 9's and Adobe was doing well. In addition to the Systems department which handled the Postscript business there was an Applications group which had Photoshop and Illustrator. John Warnock had the idea that every document that was ever printed or ever would be printed could be represented in a document. This was not an unreasonable idea since Postscript was designed for this purpose and Adobe also had some code from Illustrator that would handle the fonts and graphics and code from Photoshop to display s - this would be the second file format for the project. However there were requirements that were not being met. Requirements like forward and backwardspatibility streaming large documents through a printer driver where the printer driver has no idea how many pages there will be and opening a 1 page document and being able to jump directly to the 5th page without reading the whole file. Peter Hibberd had written a demo of an 'object oriented file format' so Richard Cohn and Alan Wootton went to work trying to adapt his work for use on the Carousel project. After many weeks of struggle it was decided that adapting his work was going to be more work than writing new code and that some of the 'object oriented' concepts were not applicable since it was finally bing obvious that a key-value format was going to be part of the solution. This was the third file format. Bob Wulff the manager of the project told Richard and Alan to 'go away' and to note back until there was a file format! The next Monday Richard and Alan started meeting at Richard's house in Menlo Park instead of going to work in Mountain View (where Google is now). By the end of Thursday Richard and Alan had described data structures and concepts for a file format on many pieces of paper. Alan went home pulled 4 overnights in a row and came back to Adobe on Monday with the fourth file format written and working in the current code. This file format became known as PDF.