Part 1: Long and Short PapersInternational audienceA User Interface Description Language (UIDL) is a formal language used in Human-Computer Interaction (HCI) in order to describe a particular user interface independently of any implementation. Considerable research effort has been devoted to defining various meta-models in order to rigorously define the semantics of such a UIDL. These meta-models cover different aspects: context of use (user, platform, environment), task, domain, abstract user interface, concrete user interface, usability (including accessibility), workflow, organization, evolution, program, transformation, and mapping. A complete development method is typically made up of the following elements: models that capture various aspects of an interactive application (compliant with the previous meta-models), a language that expresses these models, a development life cycle, and software that support this method. This Special Interest Group is aimed at presenting User Interface eXtensible Markup Language (UsiXML), a particular UIDL that is of interest to a wide audience. Then, the UsiXML End User Club is introduced so that any person, group, or organization could observe, test, or contribute to the UsiXML technology. The SIG will present the potential benefits so that everyone can use it