Abstract: In one embodiment, a method of computing comprises executing a software application, wherein the software application comprises at least first and second versions of a subroutine for performing a specific function, wherein the first version exhibits a first behavior and the second version exhibits a second behavior; and selecting for execution one of the first version or the second version based on whether one or more licensing criteria are satisfied. Optionally, the behavior of second version can be redefined on a user basis. The method can be implemented and distributed within software libraries.