Active Networks are a promising way to develop new services for data transport. Network programmable nodes can propose high level services by processing "on the fly" streams of data. In this paper, we describe how to use an active network solution to perform deployment of Java games on cellular mobiles and to face heterogeneity of platforms. We present the architecture of a transcoding service inside the Tamanoir Execution Environment. We describe the overall architecture of an active transcoding service (ActiveWapS) of JAD files and present first experimental results.