Perl documentation is written in a language known as pod (plain old documentation). Pod is a set of simple tags that can be processed to produce documentation in the style of Unix manpages. There are also several utility programs available that process pod text and generate output in different formats. Pod tags can be intermixed with Perl commands or can be saved in a separate file, which usually has a .pod extension. The pod tags and the utility programs that are included in the Perl distribution are described in Chapter 4.