Plain Old Documentation (pod) is a lightweight markup language used to document the Perl programming language as well as Perl modules and programs. Design Pod is designed to be a simple, clean language with just enough syntax to be useful. It purposefully does not include mechanisms for fonts, images, colors or tables. Some of its goals are: Easy to parse Easy to convert to other formats, such as XML, TeX or Markdown Easy to incorporate sample code Easy to read without a pod formatter (i.e. in its source-code form) Easy to write in An extended version of pod that supports tables and footnotes called PseudoPOD has been used by O'Reilly & Associates to produce several Perl books, most notably Programming Perl by Larry Wall, Tom Christiansen, and Jon Orwant. Pod makes it easy to write manual pages, which are well suited to user-oriented documents. In contrast, other documentation systems, such as Python's Docstring or Java's Javadoc, though they can be used for user documentation, are designed to facilitate generating developer-oriented documentation about the source code for a software project. Use Pod is the language used for most documentation in the Perl world. This includes Perl itself, nearly all publicly released modules, many scripts, most design documents, many articles on Perl.com and other Perl-related web sites, and the Parrot virtual machine. Pod is rarely read in the raw, although it is designed to be readable without the assistance of a formatting tool. Instead, it is read with the perldoc tool, or converted into Unix man pages or Web-standard HTML pages. It is also possible to use pod in other contexts than Perl. For example, to add simple documentation to bash scripts, which can then be easily converted to man pages. Such uses rely on language-specific hacks to hide the pod part(s), such as (in bash) prefixing the POD section with the line :<<=cut which works by calling bash's no-op : command, with the whole block of Pod as a here document as input to it. Pure pod files usually have the extension .pod, but pod is mostly used directly in Perl code, which typically uses the .pl and .pm extensions. (The Perl interpreter's parser is designed to ignore pod in Perl code.) In source code files, the documentation is generally placed after the marker (which also helps syntax highlighting in some editors to display it as comments). Pod can easily be