Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language.
Though Perl is not officially an acronym, there are various backronyms in use, such as: Practical Extraction and Reporting Language, and (more whimsicallly) Pathologically Eclectic Rubbish Lister. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. In the 1990s it became very popular for web scripting, though other languages have gained more popularity for this purpose lately.
The book Programming Perl by Larry Wall and Randal L. Schwartz (and other co-authors in later editions), ISBN 978-0-596-00492-7 or ISBN 978-1-4493-9890-3 for the e-book version, is regarded as the definitive reference for the language, and is usually referred to as "the camel book" because of the picture of a camel on the cover (in keeping with publisher O'Reilley's use of animals on its technical book covers).
Programs in Perl are usually stored in plain-text files, to be run by the Perl interpreter.
Perl 5 has been under development for years, with a number of differences from earlier versions of Perl which make programs incompatible both forward and reverse. This new version uses a virtual machine called "Parrot" with a language that is intermediate between Perl and native machine code.