1. A method for enabling creation of control flow patterns in a workflow, said method comprising: generating a plurality of continuations for one or more program fragments during execution of the program fragments by a meta-runtime engine, said meta-runtime engine virtualizing a managed execution environment having fixed functionality, each of the generated plurality of continuations representing an activity execution context; storing the generated plurality of continuations to create an execution journal for the program fragments; selecting one of the stored continuations from the execution journal and retrieving the selected continuation responsive to a request from a user; recreating the activity execution context associated with the retrieved continuation; and executing, within the re-created activity execution context, the program fragments associated with the retrieved continuation.