Alan Kay did not invent objects (2019)
27 comments
·May 7, 2025dang
Discussed at the time (of the article):
Alan Kay Did Not Invent Objects - https://news.ycombinator.com/item?id=19985776 - May 2019 (13 comments)
Rochus
Except that Wayne meanwhile added "Update 2025-05-07. I am no longer convinced that Alan Kay invented the term OOP.." to his article; I assume because of the facts that were revealed on HN (see https://news.ycombinator.com/item?id=36826762).
neilv
Alan Kay's "The Early History of Smalltalk" (1993) is long, and absolutely worth a read, and includes this memorable bit about Kay seeing Simula for the first time:
> Finally, another graduate student and I unrolled the program listing 80 feet down the hall and crawled over it yelling discoveries to each other. The weirdest part was the storage allocator, which did not obey a stack discipline as was usual for Algol. A few days later, that provided the clue. What Simula was allocating were structures very much like the instances of Sketchpad. There were descriptions that acted like masters and they could create instances, each of which was an independent entity. What Sketchpad called masters and instances, Simula called activities and processes. Moreover, Simula was a procedural language for controlling Sketchpad-like objects, thus having considerably more flexibility than constraints (though at some cost in elegance) [Nygaard, 1966, Nygaard, 1983].
taylodl
Development of Smalltalk started in 1969, and its first release was in 1972 - which is well before 1976. As far as whether Kay invented objects, no, Simula was released in 1967, well before development of Smalltalk had started. But Kay was the one to popularize objects as we think of them today.
Rochus
> But Kay was the one to popularize objects as we think of them today.
Not actually. Kay's view of OO is pretty different from what we understand of OO today; the general understanding is closer to Simula 67; see also the IEEE milestone: https://ethw.org/Milestones:Object-Oriented_Programming,_196.... Ironically Smalltalk-76 and onwards also corresponds more with the Simula 67's than Kay's view.
> Development of Smalltalk started in 1969
You mix that up with Kay's PhD. A good and reliable history about the origin and evolution of Smalltalk can be found in the excellent 2020 paper by Ingalls: https://dl.acm.org/doi/10.1145/3386335
AceJohnny2
Indeed, here's a email from Alan Kay about how his perspective is about "messaging" between objects:
https://lists.squeakfoundation.org/pipermail/squeak-dev/1998...
(edit: derp, this is directly cited in TFA)
Also, I loved this interview/discussion between Kay & Joe Armstrong, inventor of Erlang, where the topic comes up again (because Erlang is also a lot about messaging between agents)
chao-
Are you me? The timing of our posts the biggest coincidences I've experienced in quite a while.
chao-
>Kay's view of OO is pretty different from what we understand of OO today
Indeed, in his own words, from 1998:
https://wiki.c2.com/?AlanKayOnMessaging
He also gave at least two conference talks where he explained how his view of objects sending messages was in line with his background in molecular biology: he thought of the objects like cells sending messages via exchanging various chemicals. I don't have either on hand, but I believe one time he shared this was in an interview with Joe Armstrong.
Rochus
> he explained how his view of objects sending messages was in line with his background in molecular biology
I don't think he has a formal education in molecular biology (didn't find any (independent) evidence), and I don't think the analogy he draws between his view of messaging and biochemical signaling really works. His messages are directed to specific objects, whereas in a biological system, enzymes and the like are dumped into the bloodstream indiscriminately without a specific target. Biological systems, in constrast to software systems, lack centralized orchestration, relying on emergent behavior from local interactions instead.
layer8
I disagree. C++ played a major role in popularizing OOP as we know it today, and Stroustrup derived C++ from Simula.
Rochus
Yet another major role in popularizing OOP played Java, and also Gosling has publicly proclaimed that he derived the object model of Java from Simula 67.
twoodfin
OOP was well-popularized by the time Java emerged in the mid-1990’s. If anything, OOP was past the peak of the hype cycle at that time and Java gave it a renewed boost.
null
johnea
Outside the issue of OOP, Alan Kay has always been an icon to me, since I moved to Solana Beach CA in the early '80s soon after the establishment of Kaypro computers in that city.
EgoIncarnate
According to the Wikipedia page, Kaypro was created by Andrew Kay, not Alan Kay.
Interestingly both had a relationship to a NLS in there lives.
For Andrew, it was Non-Linear Systems, where Andrew invented the digital voltmeter.
For Alan, it was oN-Line System, where he attended "The Mother of All Demos", which spawned the mouse and some other inventions used in the Xerox Alto, which is where Smalltalk was primarily developed initially.
null
Ivan Sutherland released SketchPad, which is at least a precursor to OOP, in 1963. Brilliant work!
https://en.wikipedia.org/wiki/Sketchpad
https://engineeringcommunity.net/2025/05/02/ivan-sutherland/