9. A computer-implemented method that provides a customized user experience for a computing system, the method comprising: receiving a markup language file comprising one or more markup tags that generates a user interface comprising one or more user interface objects and one or more markup tags for accessing a function exposed by a computer program through an application programming interface (API); rendering the markup language file to provide the user interface; determining whether the markup language file has at least one markup language tag stored therein that references a function to be exposed by a computer program through the API; and in response to determining that the markup language file has the at least one markup language tag stored therein that references the function exposed through the API, calling the API to execute the function provided by the computer program by way of the user interface.
9. A computer-implemented method that provides a customized user experience for a computing system, the method comprising: receiving a markup language file comprising one or more markup tags that generates a user interface comprising one or more user interface objects and one or more markup tags for accessing a function exposed by a computer program through an application programming interface (API); rendering the markup language file to provide the user interface; determining whether the markup language file has at least one markup language tag stored therein that references a function to be exposed by a computer program through the API; and in response to determining that the markup language file has the at least one markup language tag stored therein that references the function exposed through the API, calling the API to execute the function provided by the computer program by way of the user interface. 10. The computer-implemented method of claim 9 , wherein the computer program comprises an operating system component.