iBooks Author software application is a freeware which is developed for Apple based operating systems. This software application uses IBA file format to save the documents created using this software.

The software is used as word processing application. The IBA file is used to store the final document and the structure of the IBA file format is similar to that of XML but there are some changings made in the structure to prevent it being readable by other applications. The working mechanism of this file format is similar to that of EPUB file format but unlike EPUB it is only readable by iBooks.