The explosive growth of the World Wide Web and the expected arrival of the fourth generation networks pose significant challenges to distributed system developers. Future distributed applications are expected to support the increasing mobility of users and to be dynamic enough to maintain the load-balancing between the different hosts constituting the distributed environment. With the evolution of the wireless technology users are increasin- gly mobile, and they expect to reach personalized information and to access specified applications regardless of their physical location. Indeed, the use of application servers allows defining efficient distributed applicati- ons, by providing tools facilitating their development, their deployment and their execution. However, even if the application servers present a powerful economic solution, they are not dynamic enough compared to the principles of the user's mobility. In our approach, we suppose that users change the hosting network regularly, and that this network has characteristic- s that do not enable users to reach the applications which they usually use in their original network. By authorizing the mobility of the applications between application servers, we enable the applications to follow the user when changing his/her original network. In this report, we propose integrating a standard service into the application servers to enable migrating hosted applications. The service makes it possible to look up, migrate and re-deploy an application on a federation of application servers while taking into account certain criteria of mobility. The service integrates two principal components: the first component allows locating the initial application and the second one performs an intelligent migration of this application.