FLUX is an interactive touch-sensitive tilting surface that can be used either as a sketching board, as an interactive discussion table, and as a digital presentation whiteboard. The surface, based on a rearprojection screen, supports both multi-touch interaction as well as multiple pen interaction with individual identification of each pen. Our setup combines two tracking technologies. For the hand-tracking, we take advantage of the Frustrated Total Internal Reflection (FTIR) technology. For the pen-tracking, we are using the tracking technology developed by Anoto. Keywords Tabletop, Digital Whiteboard, Sketching, Design Room, Design Environment, Frustrated Total Internal Reflection, Pen-based Interface, Multi-Touch. ACM Classification Keywords H.5.1 [Information Interfaces and Presentation]: Multimedia Information Systems-- [H.5.3]: Collaborative computing--Computer-supported cooperative work