1. A computer-readable storage medium having stored computer-executable instructions, which when executed perform a method, comprising: receiving a request to return content to a display of a computing system; identifying current conditions corresponding to the computing system; accessing an element tree that includes a plurality of different pieces of the content that have been provided by a developer and that each correspond to different display properties; identifying an evaluation order of the different pieces of content, wherein the evaluation order corresponds to a developer specified order for evaluating the different pieces of content based on current conditions and for selecting one of the different pieces of content to be displayed; evaluating the different pieces of the content in the evaluation order while searching for a match between the current conditions and a matching piece of the content; upon finding the matching version of the content, selecting the matching piece of the content to be returned to the display or, alternatively, upon determining that there is no match, returning a default piece of the content to the display; and returning, directly or indirectly, the selected piece of content or, alternatively, the default piece of the content to the display and in response to the request.