This collection highlights advancements in User Interface Description Languages (UIDLs), focusing on XML-based solutions for device-independent and context-sensitive user interface development. Contributions cover a range of topics including dynamic generation of multimodal interfaces, model-driven UIDL integration, and language extensibility for multi-device scenarios. Innovations in UIDL frameworks, such as UIML and USIXML, showcase methods to enhance reusability, adaptability, and scalability in HCI tools. Practical applications, case studies, and evaluations of UIDL frameworks underscore their potential in improving usability, accessibility, and integration across diverse computing environments.

We present two ongoing research efforts, both aim to support the use of models for designing (multi- and multiple-device) User Interfaces. The first tool, a part of the Dygimes framework, shows how context and tasks can be combined. It allows to generate prototype interfaces from context-sensitive task models. It builds upon a runtime environment in Java and an XML-based High Level User Interface Description (HLUID) language to generate the prototype interface. The second tool, uiml.net, experiments with another HLUID and another runtime enviroment to generate interfaces. Both tools are work in progress.

The usage of computing systems has evolved dramatically over the last years. Starting from a low level procedural usage, in which a process for executing one or several tasks is carried out, computers now tend to be used in a problem oriented way. Future computer usage will be more centered around particular services, and will not be focused on platforms or applications. These services should be independent of the technology used to interact with them. In this paper an approach will be presented which provides a uniform interface to such services, without any dependence on modality, platform or programming language. Through the usage of general user interface descriptions, presented in XML, and converted using XSLT, a uniform framework is presented for runtime migration of user interfaces. As a consequence, future services will become easily extensible for all kinds of devices and modalities. Special attention goes out to a component-based software development approach. Services represented by and grouped in components can offer a special interface for modal- and device-independent rendering. Components become responsible for describing their own possibilities and constraints for interacting. An implementation serving as a proof of concept, a runtime conversion of a joystick in a 3D virtual environment into a 2D dialog-based user interface, is developed.

Abstract. Constructing multi-device interfaces still presents major challenges, despite all efforts of the industry and several academic initiatives to develop usable solutions. One approach which is finding its way into general use, is XML-based User Interface descriptions to generate suitable User Interfaces for embedded systems and mobile computing devices. Another important solution is Model-based User Interface design, which evolved into a very suitable but academic approach for designing multi-device interfaces. We introduce a framework, Dygimes, which uses XML-based User Interface descriptions in combination with selected models, to generate User Interfaces for different kinds of devices at runtime. With this framework task specifications are combined with XML-based User Interface building blocks to generate User Interfaces that can adapt to the context of use. The design of the User Interface and the implementation of the application code can be separated, while smooth integration of the functionality and the User Interface is supported. The resulting interface is location independent: it can migrate over devices while invoking functionality using standard protocols.

Over the last few years, Model-Based User Interface Design has become an important tool for creating multi-device User Interfaces. By providing information about several aspects of the User Interface, such as the task for which it is being built, different User Interfaces can be generated for fulfilling the same needs although they have a differ- ent concrete appearance. In the process of making User Interfaces with a Model-Based Design approach, several models can be used: a task model, a dialog model, a user model, a data model,etc. Intuitively, using more models provides more (detailed) information and will create more appro- priate User Interfaces. Nevertheless, the designer must take care to keep the different models consistent with respect to each other. This paper presents an algorithm to extract the dialog model (partially) from the task model. A task model and dialog model are closely related because the dialog model defines a sequence of user interactions, an activity chain, to reach the goal postulated in the task specification. We formalise the activity chain as a State Transition Network, and in addition this chain can be partially extracted out of the task specification. The designer benefits of this approach since the task and dialog model are consistent. This approach is useful in automatic User Interface generation where several different dialogs are involved: the transitions between dialogs can be handled smoothly without explicitely implementing them.

The usage of computing systems has evolved dramatically over the last years. Starting from a low level procedural usage, in which a process for executing one or several tasks is carried out, computers now tend to be used in a problem oriented way. Future computer usage will be more centered around particular services, and will not be focused on platforms or applications. These services should be independent of the technology used to interact with them. In this paper an approach will be presented which provides a uniform interface to such services, with- out any dependence on modality, platform or programming language. Through the usage of general user interface descriptions, presented in XML, and converted using XSLT, a uniform framework is presented for runtime migration of user interfaces. As a consequence, future services will become easily extensible for all kinds of devices and modalities. An implementation serving as a proof of concept, a runtime conversion of a joystick in a 3D virtual environment into a 2D dialog-based user interface, is developed.

In this paper we describe how a component-based approach can be combined with a user interface (UI) description language to get more flexible and adaptable UIs for embedded systems and mobile com- puting devices. We envision a new approach for building adaptable user interfaces for embedded systems, which can migrate from one device to another. Adaptability to the device constraints is especially important for adding reusability and extensibility to UIs for embedded systems: this way they are ready to keep pace with new technologies.

In a time where mobile computing devices and embedded systems gain importance, too much time is spent to reinventing user interfaces for each new device. To enhance future extensibility and reusability of systems and their user interfaces we propose a runtime user interface description language, which can cope with constraints found in embedded systems and mobile computing devices. XML seems to be a suitable tool to do this, when combined with Java. Following the evolution of Java towards XML, it is logical to introduce the concept applied to mobile computing devices and embedded systems.