Modeling Cloth is an addon by Rich Colburn that gives you Marvelous Designer style cloth simulation right inside Blender. What differentiates this from the built in cloth simulator in Blender is its ability to interact with the cloth in realtime, making it easy to push and pull fabric to get the right look. Cloth can be pinned and the tool supports wind, gravity and other physics simulations. The "inflate" tool makes balloons, pillows and other such objects a breeze to create. The tool is free to download and use. Donations are accepted for those who want to help ensure future development.