In the summer of 1979, Bell Labs purchased a Mergenthaler Linotron 202 typesetter so they could typeset their own documents. The Mergenthaler was an example of the generation of typesetters just previous to laser printers. They were hideously complex and the process of producing typeset copy involved a complex and smelly photographic routine.
One of the first things that the Labs wanted to do was to produce their own fonts. Ken Thompson was especially eager to have a chess font that he could use to publish a book about chess. Mergenthaler, however, refused to give them the specs for the fonts citing the usual “proprietary nature” of the information.
But, of course, this was Bell Labs so they set out to reverse engineer the 202 and its fonts. Although Mergenthaler doubted that they would be able to do so, Ken Thompson, Joe Condon, and Brian Kernighan had everything figured out in about 6 weeks and were able to produce their own fonts and completely replace the Mergenthaler software that drove the typesetter. All this was done during “summer vacation.”
Afterwards, Brian Kernighan decided to write up what they did and how they did it in a Bell Labs memorandum later called The Vacation Memo. Mergenthaler sicced their lawyers on Bell Labs and the memo was suppressed for many years. In 2013, Professor David Brailsford, Steve Bagley, and Kernighan decided to reproduce the memo. They wanted to make it as accurate a reproduction as possible. Later, Brailsford, Bagley, and Kernighan published a paper on their reproduction in the Proceedings of DocEng 2013. Professor Brailsford tells the story of the memo and its reproduction in a very interesting and entertaining Computerphile video. It's just under 20 minutes but if you enjoy seeing our history come alive and want to appreciate how easy we have it today with our laser printers, take the time to watch it. You won't be sorry.