W3C Ubiquitous Web Domain shamrock - irish clover

Workshop on Declarative Models of Distributed Web Applications

Describing user interaction in multi-device applications from an end-to-end perspective

5 - 6 June 2007
Dublin, Ireland

Executive Summary

Web applications today involve a considerable amount of scripting both in the Web page and Web server. This workshop will discuss the potential to reduce the cost of building Web applications through the use of declarative approaches that describe what is needed at a high level, and which are easier to maintain than is the case with scripting. W3C is looking for people with knowledge in the areas of user interface and application modeling, and security and usability, who are interested in participating in discussions on Web applications involving a wide variety of devices, whether in the home, office or mobile environments.

W3C membership is not required in order to participate in the Workshop, and registration is free. You are required to submit a short statement of interest, which could be a few sentences. Please send this to <team-ubiwebws-submit@w3.org>.


The main aim of this workshop is to look at the potential for applying declarative techniques to describing Web applications, as a whole rather than just the markup downloaded to each device. Today, server-side scripts are used extensively to generate client-side markup on the fly, and the cost of developing and maintaining these scripts represents an opportunity for declarative based approaches. The emergence of XML databases and XQuery looks promising. Likewise the Semantic Web can be applied to descriptions, e.g. of device capabilities and access control, and for reasoning over them. Security and usability are key themes for realizing the potential for new kinds of Web applications, particularly, those involving richer access to device capabilities and to personal or confidential information. Another angle is the emergence of distributed applications and the potential for remotely controlling devices and user interfaces through the means to remotely exchange events.

Participants will have the opportunity to discuss application modeling, security and usability for distributed applications running on network devices. More and more devices have some kind of networking capability. W3C has hitherto focused on model-based approaches with user interface languages such as DIAL. In principle, model-based aproaches can be combined with other techniques such as dialog and goal based formalisms to describe Ubiquitous Web applications as a whole, rather than just the portions that run on particular devices. In a world of distributed applications, can we work toward common declarative languages for both user interaction and application logic? State transitions, for example, can be written in SCXML to describe application flow, as well as the behavior of individual devices in applications where multiple devices are loosely coupled via events.

The Importance of Security Considerations

An important consideration for the Workshop are the challenges raised in dealing with trust, identity, privacy and security. The current sandbox model for browsers involves the same site restriction on sending HTTP requests via XMLHttpRequest. This is inadequate for applications involving multiple devices, e.g. a browser, a remote printer and a web server, where you want to be able to exchange events with the printer. The sandbox is also a problem for richer access to device capabilities - something that is critical for Ubiquitous Web applications. One approach is to ask the user whenever the Web page wants to break out of the sandbox. This gets tedious upon repetition, and permission may be needed in advance for applications that are run in response to events, when the user may not be around to ask. Such markup may, for example, be run on a Web server rather than on a Web browser.

To avoid asking the user each time, there needs to be some means to check that the application hasn't been tampered with. This runs into problems with versioning and with pages with customized content such as the news headlines or the latest weather. Another approach is when the page is signed by an organization that the user trusts. The user can then be asked whether she always trusts applications signed by that organization. This tends to raise additional challenges, such as applying the notion of identity to Web pages, to groups of pages acting as a Web application, to devices, and to users and groups of users. A distributed framework for making assertions and making inferences on them would be valuable, and should cover trust, identity, privacy and security. Users should be aware of what they are being asked to commit to, for example, what device capabilities or sensitive information the application is seeking access to. This in itself presents significant usability challenges to avoid overloading the user, with the risk of inappropriate decisions.

There are also major usability concerns with asking the user to make trust related decisions for devices with small screens for which the entire display may be under application control and therefore at risk from spoofing attacks. One way around this is to utilize authentication mechanisms that renders spoofing attacks unprofitable, for example, by exploiting SIM-based security services that rely on the physical presence of the SIM card. Another concern is how to associate devices when they are introduced into home or office environments. For example, when using a wireless connection for printing, the printer with the strongest signal may be in an adjoining apartment, or in the office of the company located on the floor above. The usability issues for managing home networks are particularly challenging and this impacts upon security.


The following provides an indication of the topics of interest for the workshop, but other topics that fall within the workshop's scope are also welcomed:


This Workshop will help the W3C community determine what steps it can take in this area, including the possible scope of W3C Recommendations.

Position papers received for the Workshop will be posted publicly on the Web with a link from this page.

In addition, minutes and reports from the discussions, as well as a final document summarizing the outcome of the Workshop and the suggested future actions, will be posted publicly. Conversations and results are public.

Requirements for Participation

Position Papers

See Statements of Interest and Papers

Position papers are the basis for discussions at the Workshop. Accepted papers will be made publicly available. Submitting a position paper comprises a default recognition of these terms for publication. Papers should explain the participant's interest in the Workshop, and should contribute to the Workshop's goals as outlined above.

All papers should be 1 to 5 pages. Allowed formats are (valid) HTML/XHTML, PDF, or plain text. Papers in any other formats will be returned with a request for correct formatting.

The Program Committee may ask the authors of particularly salient position papers to explicitly present their position at the workshop to foster discussion. Presenters will be asked to make the slides of the presentation available on the workshop home page in HTML, PDF, or plain text. Position papers must be submitted via email to <team-ubiwebws-submit@w3.org>.

Notification of Intent to Participate

To help us with organizing the workshop, please send us an email to <team-ubiwebws-submit@w3.org> as early as possible, describing your interests and the topic your position paper will cover.


Although the Workshop is public, it is restricted to 50 places. Registration is required for all attendees. You can register online using this form.

Important Dates

Date Event
28 February 2007 Call for Participation issued
8 May 2007 Acceptance notification; registration opens
15 May 2007 Release of workshop program
22 May 2007 Deadline for registration
5 June 2007 Workshop Begins (8:30 am)
6 June 2007 Workshop Ends (6pm)

Workshop Organization

In case of any questions, please send email to <uwa-admin@w3.org>

Workshop Chairs

Organizing Committee


The Workshop program will run from 8:30 am to 6 pm on both days.


The workshop will be held at the O'Callaghan Alexander Hotel, Merrion Square in the heart of Dublin.

Hotels and Flights

We have arranged a special rate at the O'Callaghan Alexander Hotel of €165 a night twin/single, including breakfast and all taxes. We have also secured an agreement with the hotel to extend these rates to their nearby sister hotels, the Davenport and the Mont Clare.

MobileAware has made these logistical details available. You are recommended to make early reservations as Dublin is a popular destination. Here are some links to further information about Dublin:

Further Reading

$Date: 2007/08/01 11:39:10 $
Dave Raggett