I have written graphical user interfaces (GUI) programs for quasar absorption line analysis, which are available on my GitHub repository.  Programs include:

• A visual continuum-fitting program (ContFit) based on mouse clicks along the continuum.
• An absorption line finding program (LineFinder), which (using a reference line list) simultaneously displays all locations in the spectrum of the lines from the list for a given redshift.
• A spectrum stacking program (to be released shortly).