Perl is a programming language that took the world by storm. It was originally conceived as “glueware” for the UNIX environment that would fit somewhere between the command-level scripting offered by the shell and the bit-level programming made possible by using the C programming language. In fact, as early as twenty years ago, Perl was jocosely referred to as the “duct tape that holds the Internet together.” Perl was devised in a manner that encouraged extremely rapid prototyping, astonishing notational convenience, and a surprisingly wide and deep assortment of language and performance optimization techniques.
Perl is of legendary significance to the Web community because it was one of the first tools used to integrate Web services with client requests. When the earliest browsers were introduced in the 1990s, the standard programmatic approach to generating dynamic HTML content was referred to as the Common Gateway Interface (CGI). Perl and the Korn shell were the principal tools that were used to implement dynamic HTML capabilities. While the CGI approach is no longer nearly as important as it once was, Perl had succeeded at establishing itself as an essential building block of the World Wide Web. It was also the essential fourth component in the familiar LAMP (Linux-Apache-MySQL-Perl) and WAMP (Windows-Apache-MySQL-Perl) development stacks, albeit the “P” is nowadays more commonly understood to mean PHP.
Perl rapidly became a best-of-breed programming environment because of the unabashed manner in which it freely borrowed the most ingenious solution strategies from other languages and software tools. It has drawn copiously from C, the Bourne shell, the UNIX editor, and the AWK programming language. Moreover, Perl provides the capability to express arithmetical operations with extreme notational convenience—reminiscent of BASIC—and to directly implement the attributes and property lists that are so important to artificial intelligence (AI) and expert system programming—reminiscent of LISP. Further, Perl provides by far the richest library of text-processing tools based upon a full-featured syntax for specifying patterns, known as Markovian regular expressions. In fact, every other Web framework that offers pattern management paradigms originally adapted—or, frankly, stole—them from the Perl language.