1. A computer program product comprising instructions for causing a processor of a computer to initialize a virtual machine (VM) that subsequently executes an application to render an object on a display of the computer, the computer program product causing to initialize the VM by the following steps: providing a class that includes a variable, the variable being part of the application; selecting a property value that determines to selectively render the object from a first object set or from a second object set; reading an object representation for the variable from a markup language document in dependence on the property value from a first representation set or from a second representation set; and assigning the object representation to the variable in the class.