1. A client device a computer-readable storage medium storing computer-executable components, the client device comprising: a first hosting environment; a second hosting environment; a code host mechanism resident within the client device; and a body of code received by the client device to be hosted in either the first or the second hosting environment, wherein the body of code is essentially the same for the first hosting environment and the second hosting environment, wherein the code host mechanism evaluates the body of code to determine the presence of a particular function call within the body of code, wherein the function, when compiled, results in a byte signature within an executable code, the byte signature being indicative of the function call, wherein: in the event that the body of code includes the particular function call, the code host mechanism operates to cause the body of code to be hosted in the first hosting environment; in the event that the body of code does not include the particular function call, then the code host mechanism operates to cause the body of code to be hosted in second hosting environment.