Various embodiments described herein include systems, methods, software, and data structures of and for authoring and presentation of package files. Some such embodiments include instantiating a package file and receiving a presentation specification to include in the package file, the presentation specification displayable within a media playing application to provide a representation of display elements defined in the package file. Such embodiments may further include receiving content files, defining display elements for each content file, and associating each content file with a respective display element. A package file may then be generated, published, and/or displayed as a function of the presentation specification.