Anthologize turns your WordPress blog into a platform for the production of an ebook. Funded by the U.S. National Endowment for the Humanities. Output formats include…
“PDF, ePub, and TEI, an open XML format for storage and exchange.”
It’s a 0.4 alpha, but seems very promising. If you want to use it with a WordPress.com account, you’ll need to export all your content, then reimport all your content into a self-hosted WordPress install.
It seems development has stalled. Would love to see Kindle output with “round trip” linked footnotes from this.