We introduce a data reduction package written in Interactive Data Language
(IDL) for the Magellan Echellete Spectrograph (MAGE). MAGE is a
medium-resolution (R ~4100), cross-dispersed, optical spectrograph, with
coverage from ~3000-10000 Angstroms. The MAGE Spectral Extractor (MASE)
incorporates the entire image reduction and calibration process, including bias
subtraction, flat fielding, wavelength calibration, sky subtraction, object
extraction and flux calibration of point sources. We include examples of the
user interface and reduced spectra. We show that the wavelength calibration is
sufficient to achieve ~5 km/s RMS accuracy and relative flux calibrations
better than 10%. A light-weight version of the full reduction pipeline has been
included for real-time source extraction and signal-to-noise estimation at the
telescope.Comment: 10 pages (ApJ format), accepted PAS