Current visual programming environments offer a variety of composition possibilities. Most of these environments provide drag and drop facilities of components on a form and let the interaction between components be defined by selecting suitable components and checking the incompatibilities of the resulting composition. Thus, special nature of component-based development environments induces requirements for capabilities such as identification, retrieval and integration of components. This paper proposes a framework for comparing visual component composition techniques and environments. We identify basic and specific features that compose the framework and we show its use by comparing four visual composition environments.