A number of you have written us asking about interface design, Dynamic structures, and general starting tips for creating Wolfram Computable Document Format (CDF) files. I will present three examples of CDF files that will provide some insight into good practices. You should also read the recent Mathematica Q&A Series blog post about delivering CDF to your websites and blogs with the help of the CDF Web Deployment Wizard. This enables users to showcase their Mathematica projects online and share them with the global community. Let's have a look at some features that make CDF great, rising well above other platforms. For a more extensive list, please see the CDF comparison table. We will start with a short program that numerically solves the challenging problem of constrained global optimization by finding the minimum on a limited surface region. Think of finding the lowest point of an area of a mountain range. Dragging the 2D slider on the interface below automatically changes the surface geometry, and the CDF engine quickly recomputes the new minimum. This is reflected in the updated positions of the red dot. Drag and rotate the 3D graphics with the mouse to get a different view. Hold Ctrl while dragging to zoom (Command on a Mac) or hold Shift and drag to pan.