VoigtFit fits Voigt profiles to absorption lines. It fits multiple components for various atomic lines simultaneously, allowing parameters to be tied and fixed, and can automatically fit a polynomial continuum model together with the line profiles. A physical model can be used to constrain thermal and turbulent broadening of absorption lines as well as implementing molecular excitation models. The code uses a χ2 minimization approach to find the best solution and offers interactive features such as manual continuum placement locally around each line, manual masking of undesired fitting regions, and interactive definition of velocity components for various elements, improving the ease of estimating initial guesses.

PyLongslit processes astronomical long-slit spectral data recorded with CCD detectors. The software performs standard calibration steps on raw two-dimensional long-slit FITS frames, producing wavelength-calibrated 2D spectra and one-dimensional spectra for point-like sources. It supports extraction of flux-calibrated 1D spectra after detector calibrations such as bias subtraction, flat-fielding, and wavelength mapping, and includes quality-assessment plots to assist users in evaluating intermediate and final products. Designed to be instrument independent, PyLongslit works with generic long-slit spectrograph data meeting basic format and calibration frame requirements.