This paper discusses several possibilities of implementing the behavior of an object-oriented application. It assesses the use of the callback or inverse-control programming paradigm, and opposes it to a direct programming style. It presents two examples of the common approach, namely a Motif program using the main event loop, and a Java program using active objects. It then proposes a new approach, based on a limited extension to C++, that is close to Java, but that avoids some limitations of its synchronization means, discussed in the text.