The UML and OCL tool USE (UML-based Specification Environment) has been developed over more than one decade offering domain-specific languages for describing (1)~UML class and statechart models, (2)~OCL constraints for invariants~(on classes and states) and pre- and postconditions~(on operations and transitions), and (3)~SOIL (Simple Ocl-like Imperative Language) command sequences for (3a)~operation implementations and (3b)~executions of model test cases. The three languages have been originally developed as independent textual languages intended for conventional editing. This contribution introduces a new integrated development environment for the three languages allowing the developer projectional editing features. We discuss a number of advantages for model development in a user interface called USE Studio: (1)~completion mechanisms for language syntax elements and already defined user model elements, (2)~structured, focused views on related language elements (e.g., one common view on all model associations), (3)~consistency guarantees between the underlying model and model executions, and (4)~basic common refactorings for the model and model executions.