(Perl is only the most conspicuous example of a large number of popular programs that use the same algorithm; the above graph could have been Python, or PHP, or Ruby, or many other languages.

Perl is a messy, maddening programming language, the “duct tape of the internet.” But at least you can tell it was made by humans.

My colleagues use my Perl programs and some of them have cygwin installed on their PCs. cygwin has a dir.exe and my Perl programs attempt to use this when I call dir from within my program.