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>> Sean: We have had a few questions in from our
Computerphile viewers - our loyal viewers.

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There are some obvious joke ones, which
we may get to at the end, but starting with:

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"How did you start programming? Where did you start?"
>> BWK: It goes back a very long way. 

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I think this would go back into the early
1960s, or something like that, and

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therefore memory is both dim and rosy. 

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I think my first programming was probably
[in] Fortran. I tried it when I was in,
probably, my third year at university, so

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it was a long, long time ago,
and I don't remember very much about it.

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One thing I do remember is: you read the
book, you read the manual. This is

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McCracken's Fortran books, which are
really, really  good. And you read them and

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you think you understand it completely.
And then you set finger to whatever, in

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this case key punch, and you say: "Wait a
minute - what do I do?

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I don't know how to get started!"  And I
think that conceptual hump of 'how you

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get started' is still there for an awful lot
of people. You sort of know the rules of the

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language but you don't know how to say
anything. Once you're over that then it's

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easy and that's sort of true then for
all subsequent languages.  But that first

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step was hard.  So I think my first
language was Fortran; it was probably at

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university; and I also spent a summer
working at what was, at the time, Imperial

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Oil, which is a branch of Esso, and so on,
in Toronto, and I wrote COBOL there.  I was

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probably the world's worst COBOL
programmer.  Indescribably bad.

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And I haven't actually written any
COBOL since but those were the kind of

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early days.  I think I didn't really learn
to program properly until I went to

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Princeton as a graduate student and then
I actually wrote Fortran programs that

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did something, and that was more useful.
>> Sean: That was how you started programming.  This

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kind of leads on nicely from that.  What
did you think of C when you first

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encountered it? 
>> BWK: Again it's one of those
things where I don't remember and it was

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also special in that I kind of snuck up
on it because I was in the environment

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where it was going on, I had written a
little ... I had spent one summer at

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MIT when I was a graduate student.  I was
there as, in effect, a summer intern.  And

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at that point I had written in a
language called MAD, the Michigan

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Algorithm Decoder,
which a lot of the CTSS system had been

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written in.  It was really nice
because it was so much cleaner and

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neater than Fortran.  And then at the Labs
I wrote a little bit of B, which was a

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precursor to C.  B was kind of like a
stripped-down version of BCPL, which was

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done by Martin Richards at Cambridge.  And
I never, I think I never wrote any BCPL,

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but I wrote a little bit of B and it was
kind of neat and I liked it.  And then

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when C came along, it was at that point
a relatively easy transition into using

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it, and I pretty much have repressed all
of the details but I wrote programs

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early on that were doing text
processing, and although C's not the

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greatest language in the world for text
processing, at the time it was a lot

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better than any of the alternatives that
were available to me and I think period.

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And so I would I found it quite
comfortable and actually enjoyed it at that

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point and stayed that way for many many
years. 
>> Sean: Let's move on to the hardest

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challenge.  So what has been the hardest
challenge for you in your life as a

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computer scientist, which helps narrow it
down somewhat. 
>> BWK: Yeah. Geez.  I,

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I mean what are the problems
in computing are: "How do you write

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programs that work" and then "How do you
make it possible for other people to

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write programs that work?".  And it's sort
of those are the kinds of things I've

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been interested in all along.  So I want
to write my own programs and know that

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they work in some reasonable way.  And
that leads to, you know, building better

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languages, building better tools for
helping programmers, and so on.  So that's

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one aspect of it.  And the other is how do
you help other people write their

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programs too, because programming is hard
to do, programs are hard to use sometimes,

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and so that leads to, let's call it
the documentation side of life: writing

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books about programming. So that's
roughly what I would say.  Those are hard

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problems, they're not solved yet.  I think
most people have the same kinds of

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problems in various ways.  And programming
is different today than it was say 40-ish

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years ago, in the early days of UNIX.
In the early days of UNIX you had a very

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self-contained environment.  Things were
relatively small because you didn't have

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much computing power to deal with.  You
didn't have any networking issues so you

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didn't have to worry about things far
away not working or attacking

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you or anything like that.  So life was
simpler and in some ways it was more fun

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because you could build really
interesting things -- not huge but

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interesting useful things fairly quickly,
fairly small.  Today a lot more

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programming is enormous collections of
libraries that you have to .... basically

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what you're doing is gluing together
things that other people wrote, and then

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you're going to Stack Overflow to see
why they don't work. And then you're

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adding somebody else's random glue into
your own glue.  And it's in some ways not

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nearly as much fun, I think.
>> Sean:  Leading on
from a question before about

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programming languages and how it was
when you encountered C, which programming

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language is the best successor of C or
the most influential?  
>> BWK:  Those are different

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questions or they have different answers.
"Best" is a loaded word so I'll probably

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ignore it but there's some obvious
things that derive from C.  First,

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C++, which has been enormously
influential.  It was done by Bjarne

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Stroustrup while he was at Bell Labs.  Lots of
people say that C++ is too big and too

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complicated, and etc., etc., but in fact it
is a very powerful language and pretty

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much everything that's in there is in
there for a really sound reason.  It's not

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somebody doing random invention; it's
actually people trying to solve

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real-world problems.  And a lot of the
programs that we take for granted today,

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that we just use, are C++ programs.  If
you use anything from Microsoft's Office

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suite, for example, those are C++ programs.
You pick your favorite browsers, those

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are C++ programs. So C++ is in some ways,
I would argue, one of the most important

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and influential derivatives and it's the
first of the derivatives.  Another is Java,

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which in some ways is a reaction to C++.
Because C++ is big complicated, etc., and

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so Java was an attempt to simplify what
was in C++, to make more of the decisions

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for the programmers, so that the
programmer didn't have to make them

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himself or herself.  It also took
advantage of kind of ten years of

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hindsight, because Java came along the
early 90s; C++ is the early 80s, so

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there's a decade of improvement both
in our understanding of what we're doing,

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but also a decade of Moore's law, giving
us, you know, an order of magnitude or so

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of resources to work.  And therefore Java

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could use a virtual machine, which C++
was never able to do.  So there's another

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example of a derivative of C which, very
important, very influential, an awful lot

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of the services that you use at all of
these big websites, are written in

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Java as opposed to C++.  What is another
one?  I guess the obvious next one would

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be JavaScript, which takes the surface
syntax of C, as many other languages do,

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but takes the surface syntax, makes some
decisions differently -- still an

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interpreter for the most part -- but
shares that C heritage in a lot of ways

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and then goes off on its own direction.
And Javascript is, in terms of just

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lines of code being executed per day,
probably dominates all the

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others.  And then a tiny bit of
self-serving, the AWK language that Al Aho

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and Peter Weinberger and I did,
takes the surface syntax of C and then

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wraps it up in a different style.  It's an
interpreter but it looks like C with

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some variations to make it possible to
do other interesting things.  So at least

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those.  Oh! and then [a] more modern one: 'Go', for
example, a language that dates at this

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point from, I think, 2007, so it probably
hit the streets in 2009. So, call it a

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decade old.   And so Go in many ways looks
like a modern C; some people call it 'C

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for the 21st century', and it has its own
nice properties and so on.  And one of the

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things that it retains that some of the
other languages don't is more the

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minimalism that C had originally.  So
big spectrum of languages that came

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from C, inspired positively, negative
reactions, whatever, but all from that

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single source.