is based on the XML format. Its main tasks are: precise display on a variety of devices, full preservation of document structure, ability to be transformed into other formats. Unlike other popular e-book formats, fb2 does not specify the appearance options for different devices’ displays. The format employs tools to indicate the different parts of the book – verses, epigraphs, quotations.
This format was used for storing databases on the Pegasus and Palm PDA devices. Besides images, PDB allowed you to store tables, maps, e-books, and other data in a structured way. Today it has become obsolete and has been replaced by more flexible formats with DRM protection.