1. A computer program product, tangibly embodied in a machine-readable storage device, the computer program product being executed by data processing apparatus to cause the data processing apparatus to: copy a first source code component to provide a second source code component separate from the first source code component; accept user input defining a first modification at a first enhancement point within the first source code component, the first modification is an overwrite-exit modification, a pre-exit modification, a post-exit modification, a cleanup-exit modification, or a catch-exit modification, wherein the first enhancement point is provided as an implicit location in the first source code component where modifications can be incorporated and is not specifically identified in the first source code, and wherein the first enhancement point is an entry or exit point within the first source code component, a type of the first modification being based on the implicit location of the first enhancement point; modify the second source code component in response to the user input, the first source code component not being modified, the first modification to be executed at the first enhancement point; and create a compiled program based on the second source code component, the compiled program including the first modification at the first enhancement point.