Component-based software engineering is a paradigm aiming at better ways to reuse existing code and to distribute work across teams. Integrating UI components developed with different technologies can be a difficult task which can quickly can lead to code-tangling and loss of modularity. In this demo, we present a prototype framework for integrating heterogeneous UI components, using RDF and formal ontologies for unambiguous event and data exchange and minimizing dependencies between integrated components. We will show an example from the emergency management domain using components written in Java and Flex and demonstrate tight, seamless integration, including dragging and dropping objects from Java to Flex and vice versa. Author Keywords User Interfaces, Integration, Component-based Software, Ontologies ACM Classification Keywords D.2.2 Software Engineering: Design Tools and Techniques-User Interfaces; D.2.13 Software Engineering: Reusable Software--Reuse Models General Terms Design...