Would you have done anything differently in the development of Perl if you had the chance?
Either nothing or everything. See Perl 6.
What is the most interesting program that you've seen written with Perl?
I've seen an awful lot of interesting things written in Perl, maybe they are all weird. I know it's being used at the South Pole. The latest group to use it heavily are the biologists who do genetic analysis.
Have you ever seen the language used in a way that was not originally intended? If so, what was it? And did it work?
When Clearcase (revision control systems) wrote its device driver in Perl to access the file system underneath the kernel. The first surprising thing is that it worked. And the second surprising thing is that it was 10 times faster than their C code. Generally you would not want to write device drivers in Perl. Perl 6 maybe, but not Perl 5.
Has the evolution and popularity of the language surprised you in any way?
Yes and no. I definitely had experience prior to this with releasing open source software and finding that people liked it, so I already knew that if I wrote a language I liked other people would probably like it too.
I didn't anticipate the scale of the acceptance over time. Perl 5 opened up to community development, and the best thing about Perl is CPAN.
In what way do you think employing natural language principles in Perl has contributed to it's success?
That's a subject of a PhD dissertation. We use natural language — most people think COBOL — and that's not how we think about it. Rather, the principles of natural language are that everything is context sensitive and there is more than one way to say it. You are free to learn it as you go.
We don't expect a five-year-old to speak with the same diction as a 50 year-old. The language is built to evolve over time by the participation of the whole community. Natural languages use inflection and pauses and tone to carry meanings. These carry over to punctuation in written language, so we’re not afraid to use punctuation either.
What are you proudest of in terms of the language's initial development and continuing use?
It has to be the people involved. I think the Perl community paints a little picture in heaven. At the first Perl conference we met many in the Perl community for the first time and it was near my house so the family threw a party. The first thing we noticed is how pathologically helpful the people are and yet everyone was accepting of everyone's differences. The community counts diversity as a strength and that's what holds us together.