1. A mobile computing device having a processor that executes instructions for enabling a user of the mobile computing device and/or a content manager/publisher to specify what code and/or content are to be stored locally on the mobile computing device for offline use and what code and/or content are to be stored remotely for online access, said instructions when processed by said processor causing said processor to implement a mobile application engine that: processes a personalized offline web application comprising one or more web pages, web scripting code and at least one media file; applies custom web scripting code extensions to web scripting code of the personalized offline web application, said custom web scripting extensions identifying whether the associated web scripting code is to be stored locally on the mobile computing device or stored remotely in a network to which the mobile computing device may be connected; maintains a directory specifying where local files may be updated within said network when the mobile computing device is connected to the network; monitors expiration intervals set for downloaded content, whereby the content is automatically updated from the network files specified in the directory the next time said mobile computing device is connected to the network; and displays said at least one media file of said personalized offline web application without a connection to said network, wherein the downloaded content has file attributes associated therewith, said file attributes being modifiable by a user of the mobile device and/or a content manager/publisher of the downloaded content files, said file attributes specifying at least whether the associated downloaded content is to be downloaded automatically with an associated web application or in response to a request at runtime of the associated web application, and said file attributes being used by the mobile computing device to augment a file system of the mobile computing device to specify sources within the network where the downloaded content may be updated when the mobile computing device is connected to the network and when the downloaded content needs to be updated.