XUI, when used in the context of Second Life, refers to the XML User Interface framework and format, used for building the Second Life Viewer's user interface and to provide skins and translations for the it. Although serving similar purposes, it's not related to Xoetrope's java framework of the same name.
- Skinning - Broadly, the ability to customize the Viewer user interface. The Skinning project is part of the User Interface Roadmap and specifically describes a path to make the Second Life user interface entirely data driven and customizable by Linden Lab, 3rd party developers, and individuals, without requiring changes to the primary application source code, and maintainable across updates.
- Adding a dialog - Windows and dialogs in Second Life are implemented as LLFloater objects that use XML description files.