1
00:00:00,000 --> 00:00:00,540


2
00:00:00,540 --> 00:00:03,030
DAVID MALAN: --so how do we do this?

3
00:00:03,030 --> 00:00:04,702
Where do we get a compiler?

4
00:00:04,702 --> 00:00:05,410
Well most of us--

5
00:00:05,410 --> 00:00:10,590
What did you guys use back in your
day for a compiler in a development

6
00:00:10,590 --> 00:00:12,690
environment for CS50
when you took the class?

7
00:00:12,690 --> 00:00:18,270
DOUG LLOYD: So for a compiler we are
using GCC, the [INAUDIBLE] compiler.

8
00:00:18,270 --> 00:00:23,780
And in 2006 when I took CS50 we
were using nice.fas.harvard.edu.

9
00:00:23,780 --> 00:00:24,920
Do you remember that?

10
00:00:24,920 --> 00:00:27,420
DAVID MALAN: I do, which was
the new instructional computing

11
00:00:27,420 --> 00:00:28,378
environment at Harvard.

12
00:00:28,378 --> 00:00:31,130
DOUG LLOYD: Right, ice was
still there, the non-new--

13
00:00:31,130 --> 00:00:35,040
the old-- But yeah, it
was really different.

14
00:00:35,040 --> 00:00:39,150
So We didn't learn
anything about SSH-ing,

15
00:00:39,150 --> 00:00:42,170
and so most of the students in the
class were reusing Macs or PCs,

16
00:00:42,170 --> 00:00:44,045
they didn't have Linux
boxes, and so we would

17
00:00:44,045 --> 00:00:46,290
be going into the basement
of the Science Center

18
00:00:46,290 --> 00:00:49,770
where there were 30 or so computers
that have Linux environments on them

19
00:00:49,770 --> 00:00:52,241
and we would log in and use that.

20
00:00:52,241 --> 00:00:54,740
And we can only really do our
work in our accounts on there.

21
00:00:54,740 --> 00:00:55,490
DAVID MALAN: It was just
the terminal window, too.

22
00:00:55,490 --> 00:00:56,880
DOUG LLOYD: In the terminal window.

23
00:00:56,880 --> 00:00:58,880
DAVID MALAN: What did you
use for a code editor?

24
00:00:58,880 --> 00:01:01,400
DOUG LLOYD: I was an Emacs
person, Mike Smith taught Emacs.

25
00:01:01,400 --> 00:01:03,690
DAVID MALAN: I still can't figure
out how to quite out of Emacs.

26
00:01:03,690 --> 00:01:05,459
DOUG LLOYD: I can't figure out
how to quit out of Vim, so--

27
00:01:05,459 --> 00:01:06,500
DAVID MALAN: [INAUDIBLE]

28
00:01:06,500 --> 00:01:07,650
DOUG LLOYD: Yeah.

29
00:01:07,650 --> 00:01:10,090
At least we know who can use
[INAUDIBLE] if we need to,

30
00:01:10,090 --> 00:01:11,580
just so we know where to turn.

31
00:01:11,580 --> 00:01:15,450
I get the same flack for using Windows
computer in the office now, too.

32
00:01:15,450 --> 00:01:18,990
But yeah, it was certainly not
a very user friendly experience,

33
00:01:18,990 --> 00:01:21,990
particularly for somebody like me who
had never taken a computer science

34
00:01:21,990 --> 00:01:25,020
class before, to be thrust
into this Linux environment

35
00:01:25,020 --> 00:01:27,930
where everything is brand new.

36
00:01:27,930 --> 00:01:32,190
And I know when you took over the class
we sort of this conscious decision

37
00:01:32,190 --> 00:01:35,610
to make this a little better,
we suffered through nice for--

38
00:01:35,610 --> 00:01:35,670
DAVID MALAN: We still did.

39
00:01:35,670 --> 00:01:37,890
DOUG LLOYD: Not suffered through,
but we use nice for maybe two years.

40
00:01:37,890 --> 00:01:39,598
DAVID MALAN: But we
consciously introduce

41
00:01:39,598 --> 00:01:43,001
Nano, which is based on Pico, which
is a simpler text editor than both Vim

42
00:01:43,001 --> 00:01:43,500
and Emacs.

43
00:01:43,500 --> 00:01:44,010
DOUG LLOYD: Yes, much less heavy.

44
00:01:44,010 --> 00:01:46,051
DAVID MALAN: But it still
has syntax highlighting

45
00:01:46,051 --> 00:01:47,610
which was an appealing feature.

46
00:01:47,610 --> 00:01:50,553
DOUG LLOYD: Then we had
the cloud, cloud.cs50.net.

47
00:01:50,553 --> 00:01:52,927
We gave every student an
account which sort of simulate--

48
00:01:52,927 --> 00:01:53,510
DAVID MALAN: Which was
our own recreation,

49
00:01:53,510 --> 00:01:57,010
but that we had root privileges on so
we could install the software we wanted.

50
00:01:57,010 --> 00:01:57,750
DOUG LLOYD: Yeah, we could
install necessary software

51
00:01:57,750 --> 00:01:59,150
which was really good.

52
00:01:59,150 --> 00:02:02,280
But sort of the big change I
think was around 2011 or 2012

53
00:02:02,280 --> 00:02:04,530
when we had the CS50 appliance,
so students could then

54
00:02:04,530 --> 00:02:09,240
download a virtual machine
onto their existing Mac or PC

55
00:02:09,240 --> 00:02:13,770
and using a hypervisor have a
replication of their environment

56
00:02:13,770 --> 00:02:16,350
without having to go to the
computer lab or be intimately

57
00:02:16,350 --> 00:02:18,110
familiar with the Linux environment.

58
00:02:18,110 --> 00:02:18,990
DAVID MALAN: That was
actually originally

59
00:02:18,990 --> 00:02:21,492
a side effect, we had developed
the CS50 appliance really

60
00:02:21,492 --> 00:02:24,450
for our online students, the open
course, where students were following

61
00:02:24,450 --> 00:02:27,492
along passively and who really wanted
to be able to engage more actively,

62
00:02:27,492 --> 00:02:29,991
and it was only once that got
pretty table that we realized,

63
00:02:29,991 --> 00:02:32,130
wow, why don't we just use
this on campus as well.

64
00:02:32,130 --> 00:02:35,070
DOUG LLOYD: Right, so we did
that for maybe three years or so,

65
00:02:35,070 --> 00:02:36,570
constantly updating at different--

66
00:02:36,570 --> 00:02:38,490
I know we switched between
Ubuntu and Fedora a couple times.

67
00:02:38,490 --> 00:02:39,960
DAVID MALAN: It was pretty painful
keeping the thing updated though,

68
00:02:39,960 --> 00:02:40,460
honestly.

69
00:02:40,460 --> 00:02:42,690
DOUG LLOYD: I'm sure it was.

70
00:02:42,690 --> 00:02:47,355
But then it became big, it was a big
file to have to keep downloading.

71
00:02:47,355 --> 00:02:48,730
DAVID MALAN: Two gigabytes, yeah.

72
00:02:48,730 --> 00:02:54,180
DOUG LLOYD: And the CS50 IDE, by
our former colleague Dan Armendariz,

73
00:02:54,180 --> 00:02:57,060
among others I knew working
with folks at Cloud9.

74
00:02:57,060 --> 00:02:59,100
This was game changing.

75
00:02:59,100 --> 00:03:02,850
Now students can follow
along just in their browser

76
00:03:02,850 --> 00:03:04,920
and have all their
work saved to the cloud

77
00:03:04,920 --> 00:03:07,270
and it doesn't require
this huge download.

78
00:03:07,270 --> 00:03:10,680
It really changed the way that I
think students engage with class.

79
00:03:10,680 --> 00:03:13,600
I've certainly pivoted to do a lot
of my own development even in IDE,

80
00:03:13,600 --> 00:03:18,720
it's just such a great tool for
students to have, and for teachers, too.

81
00:03:18,720 --> 00:03:20,975
Teachers can share work
spaces with their students

82
00:03:20,975 --> 00:03:22,475
and help them follow along that way.

83
00:03:22,475 --> 00:03:23,370
DAVID MALAN: Yeah, a lot
of the add-on teachers.

84
00:03:23,370 --> 00:03:25,160
DOUG LLOYD: When we
used to have cloud, we

85
00:03:25,160 --> 00:03:28,230
would have the impersonate
feature or something

86
00:03:28,230 --> 00:03:31,519
so could try and help a student
out remotely for that way.

87
00:03:31,519 --> 00:03:33,810
DAVID MALAN: But what's nice,
and what was prerequisite

88
00:03:33,810 --> 00:03:36,476
before we made this move, was to
find an environment like Cloud9

89
00:03:36,476 --> 00:03:39,917
that gives terminal window, and better
yet root access for the students

90
00:03:39,917 --> 00:03:42,750
so they can install anything they
want for final projects, or tools,

91
00:03:42,750 --> 00:03:46,590
or what not, while still getting the
niceties like a graphical code editor,

92
00:03:46,590 --> 00:03:49,710
and the file browser, which really I
think don't do students a disservice.

93
00:03:49,710 --> 00:03:52,680
The reality is those are the UIs
they're using on their own computers,

94
00:03:52,680 --> 00:03:55,221
but you still have the power of
that command line environment

95
00:03:55,221 --> 00:03:57,420
and we're not abstracting too much away.

96
00:03:57,420 --> 00:04:00,720
DOUG LLOYD: Yeah, it's not like we've
taken a GUI operating system front-end

97
00:04:00,720 --> 00:04:06,100
like Cinnamon or something and just
stuck it into a web-based environment.

98
00:04:06,100 --> 00:04:07,920
You still have that
file tree on the left

99
00:04:07,920 --> 00:04:11,370
that you're really mostly working
in a terminal-based environment

100
00:04:11,370 --> 00:04:14,260
and getting students acclimated
to it fairly quickly.

101
00:04:14,260 --> 00:04:16,290
DAVID MALAN: And especially for some of
our high school students and teachers

102
00:04:16,290 --> 00:04:19,290
who don't have access to install
software on their own school's computer

103
00:04:19,290 --> 00:04:21,950
labs, game changing as you say.

104
00:04:21,950 --> 00:04:22,872