This version is a maintenance release with minor improvements, plus a new privacy-related option on the "General" tab of the "Tools | Options..." dialog:

When a document gets saved as eBook, Atlantis records the metadata used to generate this eBook:

The next time you save the same document as eBook, Atlantis automatically suggests the metadata last used to convert this document to eBook so you do not have to reenter it.

You can now set the eBook metadata history to be automatically cleared on program close.

The "Save as eBook" dialog also has a new "Custom data" box to specify additional eBook metadata:

See more release notes.