Hello World (Perl)
A simple Perl program that prints a message to the screen.
<<hello_world.pl>>= print "Hello World!\n";
In the opening of Programming Perl, Perl designer Larry Wall draws special attention to how Perl allows a short program like this one to be written without any accompanying declarations:
One thing that's easy about Perl is that you don't have to say much before you say what you want to say. In many programming languages, you have to declare the types, variables, and subroutines you are going to use before you can write the first statement of executable code. [...] But for many simple, everyday problems, you would like a programming language in which you can simply say "print "Howdy, world!\n";" and expect the program to do just that. Perl is such a language.