Computer Aided Software Engineering (CASE) tools often hinder creativity and simultaneous cooperation in early phases of system development. We have implemented a tool, Knight, that tries to overcome such problems. In order to create and manipulate a model, users draw gestures on an electronic whiteboard. Gestures are recognised incrementally and semantically interpreted as UML elements. The Knight tool integrates with existing CASE tools using component technology and XML Metadata Interchange (XMI). We discuss the implementation of the Knight tool and in particular the aspects of integration, and we show and discuss how tools can be integrated even in the context of conflicting data models.