Aspect-oriented-programming (aop) is a promising new approach where the description of a complex system/application is enchanced with various aspects, related to communication properties, distribution, synchronization, etc. All aspects can be described separately and are brought together by using a so-called weaver. Mostly, this is performed at compile-time, what makes that aspects disappear in the final software version. We argue that in some cases aspects should remain run-time entities in order to capture the dynamic properties of an application. We believe there is a need for dynamic aspects, e.g. strongly related to objects, which are clearly run-time entities.Book subtitle: ECOOP'98 WORKSHOP READERstatus: publishe