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 a definition of a user interface for the application at the mobile device. Based on the definition file, the wireless device may receive data from the application and present an interface for the application. Virtual machine software at the mobile device interprets the application definition file. This virtual machine software is extensible to take advantage of other software and/or hardware at the device.