In the context of Model Driven Engineering (MDE), models are the main development artifacts and model transformations are among the most important operations applied to models. A number of specialized languages have been proposed in order to specify model transformations. The OMG has, for instance, adopted the QVT specification. Apart from the software engineering properties of transformation languages, the availability of high quality tool support is also of major importance for the industrial adoption and ultimate success of MDE. In this paper, we present ATL: a QVT-like model transformation language and its execution environment based on the Eclipse framework.