The W3C has acknowledged receipt of a submission from MartSoft Corporation for a proposed Extensible User Interface Protocol (XUP). XUP is "a SOAP-based protocol for communicating user interface events and updates on the web. Once a session has been established between a client and server, user interface events can be passed to server-side handlers; these in turn, pass back updates to the user interface. XUP provides a foundation for developing and consuming highly interactive web applications and services. XUP is independent of the actual UI or event model: it places no restriction on the UI component set, or the attributes or events associated with each component. Furthermore, it supports both delegation and capturing/bubbling event models. XUP can work with any UI models with XML-based representations. A UI model is described by a tree of XML elements, with UI components (e.g., panels, buttons) mapping to elements and the properties (e.g., color, size) of the components mapping to attributes. Examples of XML-based UI models include XUL, Proto, XHTML, and WML." According to the W3C comment, the XUP submission "has a direct relationship to the goals of the W3C Multimodal Interaction Activity to develop markup specifications for synchronization across multiple modalities and devices with a wide range of capabilities."

Bibliographic information: XUP - Extensible User Interface Protocol. W3C Note 28-May-2002. Edited by Jin Yu (MartSoft Corporation) and Jun Chen (MartSoft Corporation). Submission date: March 20, 2002. Version URL: http://www.w3.org/TR/2002/NOTE-xup-20020528/. Latest version URL: http://www.w3.org/TR/xup/.

XUP description [excerpts]:

XUP provides a model that bridges between the traditional desktop based and web page based user interface paradigms. With XUP, events are delivered from user agent to server as SOAP messages. Programmers implement event handlers on the server side. They no longer need to process form data as URL-encoded strings. User interface changes are delivered from server to user agent as incremental updates, so end users will no longer experience slow page refreshes, and network bandwidth is conserved.

The traditional desktop-based model offers rich and powerful user interface controls, but it requires client-side software administration. The web page based model has no client software administration cost, as it has a universal client--the web browser, but it lacks sophisticated user interface controls required by highly interactive web applications. XUP provides a foundation for a user interface programming model that combines the advantages of both the desktop and web page based models. XUP offers the benefit of zero client administration cost as well as better, richer, and more powerful user interactivities. The XUP based model complements, rather than replaces, the traditional desktop or web page based models. The desktop model is more appropriate for graphics-intensive applications, such as movie players and video games, and the web page based model is more suitable for information browsing, such as browsing news web sites...

An XUP request is encapsulated in a SOAP envelope. The header blocks of the SOAP envelop form the XUP request header, and the body blocks of the SOAP envelope form the XUP request body. Similarly, an XUP response is also encapsulated in a SOAP envelope. The header blocks of the SOAP envelope form the XUP response header, and the body blocks of the SOAP envelope form the XUP response body. If error occurs when processing a request, an XUP server must generate a SOAP fault and return it in the response body...

From the W3C Team Comment on the XUP Submission: "The submission has a direct relationship to the goals of the W3C Multimodal Interaction Activity to develop markup specifications for synchronization across multiple modalities and devices with a wide range of capabilities. The Multimodal Interaction Working Group is investigating the means to extend W3C's XML event model across the Web, as a possible basis for coupling distributed components in a multimodal system... The submission will be brought to the attention of the Multimodal Interaction Working Group as input into work on using events to couple distributed components in a multimodal system. It may also be of interest to the XForms Working Group as a possible means to implement the binding to the user interface..."

From the IPR statements: "MartSoft Corporation hereby grants to the W3C, a perpetual, nonexclusive, royalty-free, world-wide right and license under any MartSoft Corporation copyrights in this contribution to copy, publish and distribute the contribution under the W3C document licenses. Additionally, should the submission be used as a contribution towards a W3C Activity, MartSoft Corporation grants a right and license of the same scope to any derivative works prepared by the W3C and based on, or incorporating all or part of, the contribution. MartSoft Corporation further agrees that any derivative works of this contribution prepared by the W3C shall be solely owned by the W3C. MartSoft Corporation agrees that, upon adoption of this submission as a W3C Recommendation, it will grant to any party ('licensee') a Royalty-Free licence under MartSoft Corporation's applicable intellectual property rights essential to implement the Recommendation. One precondition of any such license granted to the licensee shall be the licensee's agreement to grant to MartSoft and other companies reciprocal royalty-free licenses to any intellectual property rights owned or controlled by the licensee necessary to implement the Recommendation. MartSoft expressly reserves all other rights it may have..." [see draft W3C Patent Policy Working Group Royalty-Free Patent Policy]