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Re: Alan Kay on the meaning of "object oriented"

In the Simula-67 25 years anniversary in Oslo in June 1992, several people were present to tell about how Simula had influenced their thinking. Ole Johan Dahl and Kristen Nygaard were there, of course (they are now both dead).

Alan Kay (then Apple), Peter Wegner, Larry Testler, Bjarne Stroustrup (AT&T) and the mentioned Simula inventors Dahl and Nygaard were there.

I assume that people at the University of Oslo would have film taken from this quite big event.
It was arranged by Institututt for informatikk, Norsk regnesentral and  Den norske dataforening.

Translation from my Norwegian written minutes. Don't take any of this for historical facts! They are only my minutes!

Alan Kay's lecture was called "How Simula hit me on the head, and how I have never been the same since". I actually found the qoute at http://eiffelzone.com/d/quotes80s90s.html when I searched for it.

Alan Kay said that he built on Simula when he was with Xerox-Parc and developed the windows based GUI and Smalltalk. He had read the assembly code paper listing of the Simula compiler. In 1962 he had developed Sketchpad. He showed a film showing the GUI of it. This was object oriented.

When he was a graduate student in Utah he was given a thick listing of a compiler. He had been told that "here is an Algol compiler and it does not work". He said, no wonder, since it was Simula! Reading that listing "changed his life". On one side, Sketchpad was beautiful, but he did not have any programming model for it, Alan Kay told. Therefore, it was difficult to see that Sketchpad was beautiful. With Simula everything could be expanded, one could handle complexity. He said something about complexity and biology: 45 cell divisions make a baby etc. He was a biology major (My minutes show that I did not understand this)
He said that "Simula said that data-structures and procedures are bad ideas". This was fantastic! he said. One wanted objects which themselves knew what to do. The basic idea of OOP is "wrap it up and make an API out of it".

From November 66 to late 1972 the ideas had deleoped into Smalltalk. It solved how to get away from loops and all that. He was not actually interested in programming languages, but personal computers. He then made a PC which was developed based on Simula. Types were removed. He called it the "FLEX-machine", and it had a "when" clause. Seymore Paper did something similar with children in 1968. This interested him a lot. So he deleoped Dynabook 1972-73. At least in thoughts. Then he had an early Apple and Smalltalk-72 on a 5 MIPS machine. It had no procedure calls.


By the way, at that event I got Stroustrup, Hoare, Kay, Nygaard and Dahl's autograph (signature). I still treasure them!
Hoare said at CPA-2007 in Surrey that he remembered that meeting.

Med vennlig hilsen / sincerely
Øyvind Teig

Øyvind Teig
Senior utviklingsingeniør, M.Sc.
Autronica Fire and Security AS
A UTC Fire & Security Company
Tlf: +47 7358 2468 / Faks: +47 7358 2502 / Mob: +47 9596 1506
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http://home.no.net/oyvteig/pub - Publications

Allan McInnes <allan.mcinnes@xxxxxxxxx>
Sent by: Mailing_List_Robot <sympa@xxxxxxxxxx>

10.11.07 03:11

        To:        occam-com@xxxxxxxxxx
        Subject:        Re: Alan Kay on the meaning of "object oriented"

Another somewhat relevant Alan Kay quote comes from his OOPSLA 1997  
keynote (available via Google Video at http://video.google.com/
videoplay?docid=-2950949730059754521 -  the comment in question  
appears roughly 10 min 30 sec into the speech):

    "...I made up the term object-oriented — and I can tell you I  
did not have C++ in mind..."

It's probably worth noting the Kay's early work on Smalltalk is part  
of what inspired Carl Hewitt to develop the Actors model of  
concurrency (which has formed the theoretical basis of several  
languages, in the same way that CSP informs occam). Unfortunately,  
the concurrent aspects of Kay's OOP model seem to have got lost  
somewhere early in the piece, and when concurrency got grafted onto  
OO languages again later, it came in the form of threads and shared  


On Nov 9, 2007, at 3:43 AM, Tom Locke wrote:

> I didn't know that Alan Kay originally coined the term "object  
> oriented programming". It seems he was *very* close to our way of  
> thinking back in those early days (late 60's).
> ----
> - I thought of objects being like biological cells and/or individual
> computers on a network, only able to communicate with messages (so
> messaging came at the very beginning -- it took a while to see how to
> do messaging in a programming language efficiently enough to be
> useful).
> ----
> Too bad it went so wrong
> http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht24Ht/doc_kay_oop_en
> Tom