The Kaessaron, by Brian Paul Kaess, is an inverse of the Diatessaron by Tatian. It includes the biblical material Tatian specifically left out, as well as adding new genealogical and biblical insights of its own. Kaessaron is merely a pun or spin on the ancient title Diatessaron, and does not equate with meaning of the greek Diatessaron, which means 'out of... four.' In the Kaessaron, there are nine main portions, and its primary focus is on including missing elements of the four gospels not found in the Diatessaron as well as including Kaess genealogy, etc. - this effort resulting in nine main parts. Illustrations are shown that illuminate certain portions. Therefore, the Diatessaron is a 'gospél harmony,' whereas the Kaessaron is more a biblical & genealogical amalgam.
Brian Paul Kaess (Sun,) studied this question.