The design of 3-dimensional integrated circuits requires new specialized tools, methods and flows. Whereas some tools are on the market and some design flows for standard ICs are extended to handle die stacking and through-silicon vias, much R&D has still to address relevant and crucial problems. We can roughly classify design problems and tools into three categories: i) synthesis of 3D structures, ii) analysis, verification and test support, and iii) thermal management. We briefly surveynmethods and tools addressing these problems.