Modification of program code for execution in a multi-tenant or distributed computing environment

Program code, such the program code of an application program, can be modified to permit the program code to execute in a multi-tenant execution environment. For example, program code might be modified at compile time, run time, or at another time, in order to enable the program code to properly operate in an execution environment in which applications might be simultaneously executed in process by multiple tenants. Program code might also be modified at run time to enable the program code to execute in a distributed fashion in a distributed computing environment. For example, portions of the program code might be configured at run time to execute in different instances of an execution environment. The program code might be modified at run time to enable the program code to properly execute in multiple instances of the execution environment.