Kay was working at Xerox Palo Alto Research Center in the early 70s, in the extraordinary time when that centre invented most of the computing technologies we rely on today - windowing systems, the graphical user interface, bitmapped displays, laser printers, local networking and so on. Kay was one of the originators of object-oriented programming and invented the Smalltalk language with which software on many of the Xerox computers was built.
So Kay's article was informed by the absolute cutting edge of technology. He envisions a small portable computer, the size of a notebook (12" by 9", 30cm by 22cm), weighing no more than 4lb (1.8 kg), with plenty of onboard storage, a print-quality LCD screen, and a keyboard that could either be part of the hardware or virtual. The device would allow the user to read documents, and have ready networked access to libraries for downloading books. It would be cheap enough and easy enough to use that most people (adults and children) would have their own device and take it everywhere with them. In other words, it's what we have today in our tablet computers and small laptops, and various articles have been written comparing the Dynabook concept to the Apple iPad or to netbooks.
The differences are interesting, however. Kay's driver in the article is not really technology, but education. He begins by bemoaning the poor use of technology within education, observing that most educational machines have not worked well, and saying that his goal in the article is to "discuss some aspects of the learning process which we feel can be augmented through technological media". He then progresses to have a case study of two nine-year old children using their Dynabooks to play a video game. It doesn't do what they want, so they revise it on the spot - because it turns out that the Dynabook is not just a passive device but can be programmed at will. The children research the physics of the game using the library function and then reprogram it so that it works more realistically.
Kay proceeds to introduce a considerable amount of learning theory - Montessori, Jean Piaget, Jerome Bruner, Seymour Papert - and argues that "computers are an almost ideal medium for the expression of a children's epistemology". Only then does he introduce the hardware design that has proved so influential. In passing, he discusses issues like copyright and advertising on such devices. But it is clear that his goal is education - he argues near the end that "We do feel that the pedagogical merits of teaching algorithmic thinking, having easy editing etc. (all wrapped up in an environment which can go anywhere and can belong to anybody), are undeniable."
He admits near the end of the article that a certain amount of it is "speculation and fantasy", but he knew well that most of what he envisaged was either technologically possible in 1972 or would become so over the next few years. In that respect, it's amazing it took us so long. The tech community has long taken the Dynabook as a template, of course. I well remember as an undergraduate in Cambridge, c1990, being told by some computing entrepreneur (I forget who) that the Dynabook had not been possible until that moment, but now he was going to produce it. And every time a portable device arrives it's compared to the Dynabook at some point. But it really does feel like we have the hardware in place now.
So did Alan Kay invent the future? Well, yes and no. Tablets and netbooks are certainly (fairly) cheap, very widespread (at least in rich countries), portable and easy to use. But what's very clearly missing is the active element, especially regarding programming. Tablets are used to surf the net, check and reply to emails and social media, watch video, listen to music, read books and magazines. Netbooks do many of the these things too - the reading and watching not quite so well, but with better keyboards they work better to create and edit documents. But both these device categories are passive in terms of the computing environment - you take things you're given. Apps for iPads and Android tablets aren't created on the tablets but on 'proper' computers with bigger screens and full keyboards. And while children might research their homework using a tablet, they're unlikely to be recreating a physical environment on one from scratch.
The Dynabook was, and is, a revolutionary concept. But it's a revolution that's still unfinished.