PCAST (iTunes Podcast) is a special type of XML file developed by Apple Inc., used for sharing podcasts with their iTunes application.

PCAST files allow iTunes users to subscribe to various podcast feeds. However, they contain no audio data on their own, but just a reference to the location of the latest podcast episodes.

A standard PCAST file is an XML file fully compliant to the RSS 2.0 Specification. It usually contains special iTunes RSS tags, which specify additional information about the author and topic of the podcast. The iTunes RSS tags may be also used to define things such as: a set of keywords that describe the podcast in greater detail, a brief summary of the podcast topic, or a category that the podcast fits into.

A special tag defines the URL, length (in bytes) and MIME type of the podcast. Supported audio-only file types are MP3 and M4A. However, certain PCAST files may also carry information about video podcasts. Being an XML file, besides iTunes, a PCAST can be easily opened with any text editor for further tweaking and/or data extraction.

New PCAST files can be easily created by just dragging a podcast feed a user is subscribed to from the iTunes app interface directly to the desktop.