Data Reduction Software of the X-shooter Spectrograph

We present the Data Reduction Software (DRS) being developed at APC, Paris Observatory, Amsterdam University and ESO for the X-shooter echelle spectrograph. X-shooter is the first VLT second generation instrument, expected to be operational in 2008. The DRS will be fully integrated in the ESO VLT system and it will use the ESO Common Pipeline Library. We discuss the data reduction related to slit and IFU observations. X-shooter data have two main characteristics, on the one hand the exceptionally wide band (0.3-2.4 mum) covered in a single exposure, and on the other hand the spectral format with highly curved orders and tilted lines. The reduction process is described and the critical issues related to the above characteristics, notably the sky subtraction, the optimal extraction, and the construction of 1D/2D/3D output products, are addressed. Some aspects of the spectrophotometric calibration are also discussed.