TanDEM-X is an innovative mission with a TerraSAR-X add-on satellite for high-resolution single-pass SAR interferometry. The TanDEM-X mission has the primary objective of generating a consistent, global DEM with an unprecedented accuracy according to the HRTI-3 specifications (2 m height accuracy, 12 m posting). Beyond that, TanDEM-X provides a configurable SAR interferometric platform for demonstrating new SAR techniques and applications. The launch of TanDEM-X is planned for 2009. This paper gives a short overview of the TanDEM-X mission concept, summarizes the basic products and gives several examples of new interferometric techniques that will be demonstrated with TanDEM-X.