Files with the .EBK extension contain compressed and encrypted files with the formatted contents of an e-book. The publication file must first be saved in an HTML-webpage format. Then, the eBook Pro software, made for creating copyrighted EBK files, converts said files in the HTML format into EBK files, which can be opened using the eBook Viewer.

What is more, with the use of a special program extension, e-book creators and sellers can expand their products’ distribution – specifically, manage the online access permissions.