We introduce Unified e-Book Format (UeBF) and an example Hybrid Library 2.0 application model based on it. The UeBF is a file format for storing electronic books and related metadata we have designed and developed. It differs from other electronic book file formats in its ability to store an electronic book in multiple file formats and related metadata using multiple metadata standards, all in a single file. The format is open and extensible, and the contents can be accessed using a ZIP file archiver. Using the said file format, we have succeeded in designing an application model that combines the Hybrid Library and Library 2.0 concepts. We named it Hybrid Library 2.0. It leverages the advantages of a Hybrid Library using the UeBF, like the ability to provide users with paperback and electronic books, and offers Web 2.0 presentation possibilities, such as user interactivity, social aspects and a multimedia experience.