This episode is about OSGi, the dynamic module system for Java. Our guests are Peter Kriens (OSGI's Technical Director) and BJ Hargrave (OSGI's CTO). We'll discuss what OSGi is all about and why and in which contexts it is useful. Additionally we are having a look at the different layers of OSGI and where and how they are used. Other questions discussed are: What means dynamicity in an OSGI environment? Where is OSGI used? What’s the future of OSGI? How does OSGI interact with existing middleware solutions? How can I run several versions of the same JAR at the same time? Where are OSGI’s problems?