:15:01
were developing their own free
operating system.
:15:05
Known as Berkeley Unix, or BSD,
:15:08
it was based upon the Unix kernel
which had been licensed from AT&T.
:15:13
However, due to legal problems with AT&T
and fragmentation of the source code,
:15:18
hackers and other non-institutional users
were slow to adopt it
:15:23
Well, Unix consisted of a large number of
separate programs
:15:28
that communicated with each other.
:15:30
So we just had to replace these programs
one by one.
:15:34
So what I started doing was
writing a replacement for one program,
:15:39
and then another, and then another,
:15:41
and then people started joining me,
:15:43
because I published an announcement
inviting other people to join me
:15:47
to help write these programs.
:15:50
And uh... and by around 1991,
we had replaced practically all of them.
:15:59
[ What were some of the programs that you ... ]
:16:01
Well... we had to... to have a complete system,
:16:05
you need to have a kernel, which is the program that
:16:09
allocates resources to all the other programs,
:16:13
you need a compiler, which translates a program
:16:17
from readable source code
that programmers can understand into numbers,
:16:23
mysterious numbers
that the computer can actually run.
:16:29
you need other programs
that go with the compiler to help do this job.
:16:32
you need a debugger.
:16:33
you need a text editor.
:16:35
you need text formatters.
:16:36
you need mailers...
:16:39
you need lots and lots of things.
:16:40
There are hundreds of programs
in a Unix-like operating system.
:16:45
I saw Stallman's announcement.
:16:47
Actually I met him in February of 1987.
:16:51
He came to give a five-day tutorial
on Emacs at our company.
:16:57
And during the day he would explain