In computer programming, Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall, a linguist working as a systems administrator for NASA, in 1987, as a general purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and became widely popular among programmers. Larry Wall continues to oversee development of the core language, and its newest version, Perl 6.

Perl borrows features from other programming languages including C, shell scripting (sh), AWK, sed and Lisp. The language provides powerful text processing facilities without the arbitrary data length limits of many contemporary Unix tools,

History

Larry Wall began work on Perl in 1987, while working as a programmer at Unisys, and released version 1.0 to the comp.sources.misc newsgroup on December 18, 1987. The language expanded rapidly over the next few years. Perl 2, released in 1988, featured a better regular expression engine. Perl 3, released in 1989, added support for binary data streams.

Originally the only documentation for Perl was a single (increasingly lengthy) man page. In 1991, Programming perl

Perl 4 went through a series of maintenance releases, culminating in Perl 4.036 in 1993. At that point, Wall abandoned Perl 4 to begin work on Perl 5.

Initial design of Perl 5 continued into 1994. The perl5-porters mailing list was established in May 1994 to coordinate work on porting Perl 5 to different platforms. It remains the primary forum for development, maintenance, and porting of Perl 5.

Perl 5 was released on October 17, 1994. It was a nearly complete rewrite of the interpreter, and added many new features to the language, including objects, references, lexical (my) variables, and modules. Importantly, modules provided a mechanism for extending the language without modifying the interpreter. This allowed the core interpreter to stabilize, even as it enabled ordinary Perl programmers to add new language features.

As of 2008, Perl 5 is still being actively maintained. Important features and some essential new language constructs have been added along the way, including Unicode support, threads, improved support for object oriented programming and many other enhancements.

On December 18, 2007, the 20th anniversary of Perl 1.0, Perl 5.10.0 was released. Perl 5.10.0 includes notable new features, which bring it closer to Perl 6, among them a new switch statement (called "given/when"), regular expressions updates, the "smart match operator" ~~, and more.

One of the most important events in Perl 5 history took place outside of the language proper, and was a consequence of its module support. On October 26, 1995, the Comprehensive Perl Archive Network (CPAN) was established as a repository for Perl modules and Perl itself. At the time of writing, it carries over 13,500 modules by over 6,500 authors. CPAN is widely regarded as one of the greatest strengths of Perl in practice.