Software, devices and methods allowing varied mobile devices to interact with server side software applications are disclosed. Data from an application executing at a computing device is presented at a remote wireless device by providing the device an application definition file, containing definitions for a user interface format for the application at the wireless device; the format of network messages for exchange of data generated by the application; and a format for storing data related to the application at the wireless device. Using these definitions, the wireless device may receive data from the application in accordance with the definition and present an interface for the application. Preferably, the application definition file is an XML file. Similarly, application specific network messages provided to the device are also formed using XML. Data from the application may be presented at the mobile device by virtual machine software that uses the application definition file.