ePublishing User Interface Design is a key factor in the success of an interactive eBook publication, as the User Interface allows the reader to navigate through eBook content, and even interact with the content.

eBook User Interface Design for ePub Documents requires expert knowledge of 3D Modeling, Texture Mapping and Animation, Digital Image Compositing and Image Optimization, CSS and XML Mark-Up, XHTML and HTML5 Programming, as well as User Interface Design.

Clever ePub User Interface Design can set one eBook ePublishing Title apart from other similar titles in the ePublishing marketplace. eBook UI Design is especially important for highly visual titles such as interactive children's storybooks, as the content navigation can be seamless with visual imagery that comprises a visual story for a child.

Notice on this page (developed using the same XHTML1, CSS2, PNG and aGIF used in the current ePub 2.01 format released in 1997) how seamless the 3D User Interface and background animations are together, forming a visual User Experience using only a few hundred kilobytes of data and around two dozen lines of programming code. All coded in only four content containers, a header (advertising can live here), the user interface (on the left and bottom) and the main content area. All feature 3D and special FX animation.