FUB stands for Franklin Universal Binary. It is the eBook format for the Franklin eBookMan reader. A file in this format will have a .fub extension.
SEB stands for Secure eBookMan Binary - Most eBooks purchased from the Franklin ebook site will have this extension. This book format contains DRM content.
 Readers for this format
The Franklin eBookMan Reader is no longer being made or sold although you can find one on ebay from time to time. The program used to read FUB and SEB files on this hardware was called the Franklin Reader.
 Format Information
Features supported by the format include TOC, Graphics, Bookmarks, Bibliography, Footnotes, tables, and cross references.
There are some special features in the file format to support specialized eBooks such as dictionaries, Bibles, Medical Books, and Translation books.