I am well aware that Eohan contains mistakes. Nothing in it should be cited as the work of Karlgren, Pulleyblank or Baxter. I am a language hobbyist with an extensive knowledge of historical linguistics but I do not know Chinese, I am working at the limit of my ability and I have taken the project nearly as far as I can go. It is also clear that the ongoing reconstruction of Old Chinese cannot be reproduced algorithmically for reasons given by Baxter and Sagart in Old Chinese: a new reconsruction (2014). This site uses Baxter's earlier Old Chinese (1992).
One of my motivations is to place an important body of information about Chinese historical linguistics online and in the public domain. I am hopeful that Eohan may be of use to those trying to understand issues such as the origin of the northern tonal system and the interpretation of the four grades.
Anyone wishing to take the project further is welcome to use my code and datasets with acknowledgements. I believe that my data sources are in the public domain and that I make fair use of the work of Karlgren, Pulleyblank and Baxter.
If I return to Eohan myself, I intend to add material from Menggu Zidian, Qi Lin Bayin and Qieyun and to add the fanqie of the individual characters in Guangyun or Qieyun. If you know of open source digitisations of these or any other relevant texts, please let me know.