The meta-level protocol of Guaranį was designed in a way that makes it possible to create libraries of meta-objects that implement specific meta-level behaviors, and to easily compose them into complex meta-configurations. A good example of this is MOLDS [27], MOLDS, a Meta-Object Library for Distributed Systems, that provides meta-objects for persistence, distribution, replication, atomicity and migration. Guaranį and MOLDS are parts of a larger project [5].