Files with the POD extension are associated with Perl, a high-level, interpreted, dynamic programming language developed in 1987 by Larry Wall. POD is an abbreviation for Plain Old Documentation. The POD format uses a simple markup language with limited syntax for documenting the Perl programming language.

This includes almost all released modules, a wide variety of scripts, articles on Perl-related websites, design documents, the Perl help manual and the Parrot Virtual Machine.

POD documentation can be saved as POD files and can also be used directly in Perl code. The simple syntax of the POD markup language makes it easy to parse, easy to read in its source code form, easy to convert and easy to write.