You can find an RSS/XML feed for individual playlists or your entire item library in Platform.
To get an RSS feed for a playlist, head to Playlists and click the actions dropdown on the desired playlist. and select "XML Feed".
To turn this into an iTunes-compatible Podcast feed, create a new feed and link it to the playlist.
To retrieve an XML/RSS feed for your whole (published) library, head to the platform homepage and click either the RadioPlayer or RSS feed logo at the bottom of the page.