Cool Navigate researches strategies for the development and execution of adaptive Web applications in mobile scenarios. Depending on properties of the client devices and mobile communication facilities, we strive for an energy-optimized application use. A client-server distribution of application components is performed depending on the energy state of the mobile device. In case of a high battery charge state, resource-intensive parts of the application can be run directly on the mobile client, which may result in an increased ease of use. If the battery level is low, the client is operating in power save mode, whereas more computing power is delivered by the server to execute application components.