Visual Studio 2010 comes with a set of integrated modeling tools that enable architects and developers to design and plan their software systems. By combining these designers with T4 and custom DSLs, you can create rich new experiences for customized code-generation, documentation, or other models. This is enabled through a rich set of extensibility features that can enable architects and development teams to customize their experience with simple MEF-based extensions. In this session see first-hand how the extensibility features work as we start with the in-the-box UML designers and then build a succession of extensions. These extensions show you how to customize the experience to your way of working, and how to generate code and documentation from a combination of UML and DSL models.