Modern GUI toolkits, and especially RIA ones, propose the concept of binding to dynamically link domain data and their presentations. Bindings are very simple to use for predefined graphical components. However, they remain dependent on the GUI platform, are not as expressive as transformation languages, and require specific coding when designing new graphical components. A solution to such issues is to use active transformations: an active transformation is a transformation that dynamically links source data to target data. Active transformations are however complex to write and/or to process. In this paper, we propose the use of the AcT framework that consists of: a platform-independent mapping language that masks the complexity of active transformations; a graphical mapping editor; and an implementation on the .NET platform.