Status, performance, and first results of the IceTop array

We describe the design and performance of IceTop, the air shower array on top of the IceCube neutrino detector. After the 2008/09 antarctic summer season both detectors are deployed at almost 3/4 of their design size. With the current IceTop 59 stations we can start the study of showers of energy well above 10${}^{17}$ eV. The paper also describes the first results from IceTop and our plans to study the cosmic ray composition using several different types of analysis.