The VPFIT program fits multiple Voigt profiles (convolved with the instrument profiles) to spectroscopic data that is in FITS or an ASCII file. It requires CFITSIO (
ascl:1010.001) and PGPLOT (
ascl:1103.002); the tarball includes RDGEN (
ascl:1408.017), which can be used with VPFIT to set up the fits, fit the profiles, and examine the result in interactive mode for setting up initial guesses; vpguess (
ascl:1408.016) can also be used to set up an initial file.