This paper reports on the dynamic adaptation of multimedia services for both mobile and fixed terminal devices. The adaptation is done based on the device features and includes both the adaptation of the presentation format (e.g. HTML, WML, SMS, E-mail and speech driven browsers) as well as the multimedia contents. The services are defined in XHTML with some extensions. In this paper, we mainly focus on the considerations involved in the development of the adaptation methodology. The architecture of the system is also briefly described. The research is part of the Princess project, a joint project of Oulu University and VTT Electronics.