All packages are for the Windows world and all are freely available from the authors, either by a straightforward download or on request. In most cases emphasis has been placed on being able to carry out graphical analysis based on Looms-Wood type plots of recorded spectra. In this respect the interactive Loomis-Wood program developed in the Winnewisser laboratory in Giessen, Germany was of pioneering importance.

        The current packages can be subdivided into several groups. The first group consists of those that stem from applications in rotational spectroscopy:

AABS, CAAARS, DAPPERS, JB95, LLWP, SMAP (in alphabetical order)

        A second group of packages results from analysis of vibration-rotation spectra in the infrared:

ATIRS, Giessen Loomis-Wood, INFIA, Loomis-Wood Add-In, LWW, PGOPHER, VMS-ROT (also in alphabetical order)

        Most of these packages, especially those based on the SPFIT/SPCAT engine for fitting and prediction, should in principle be able to deal with both pure-rotation, rotation-vibration and vibronic spectra.

     
        The impulse to write this package came from the need to deal with FASSST spectra on relatively low-end computers. The package turned out to be very useful for the analysis also of the MMW rotational spectra recorded in our Warsaw laboratory, of supersonic expansion FTMW spectra, and of rotation-vibration spectra from several synchrotron radiation based FTIR spectrometers.

        AABS can use several different packages for fitting/prediction.  The input/output of two packages can be used directly, and these are:
        ASFIT/ASROT - straightforward asymmetric rotor treatment up to decadic terms,
        SPFIT/SPCAT - general Hamiltonian for up to six quantum numbers.
Two additional packages can be used by means of available input/output reformatting programs:
        ERHAM - Effective Rotational HAMiltonian fit,
        RAM36 - Rho Axis Method internal rotor fit.

        The AABS package has been described in:

• Z.Kisiel, L.Pszczolkowski, I.R.Medvedev, M.Winnewisser, F.C.De Lucia, E.Herbst, J.Mol.Spectrosc. 233,231-243(2005)

        A list of applications is in Table 2 of:

• Z.Kisiel, L.Pszczolkowski, B.J.Drouin, C.S.Brauer, S.Yu, J.C.Pearson, I.R.Medvedev, S.Fortman, C.Neese,
  J.Mol.Spectrosc. 280,134-144(2012)

   
        This originated as an in-house package to deal with the FASSST spectra recorded at Ohio State. The package has been used intensively in many different analyses by the OSU Microwave Group.  It has been designed to use SPCAT/SPFIT, and there are rumours that it also works with Peter Groner's ERHAM.

        CAAARS is actually an add-on to the commercial IGOR PRO program, so you have to buy that first.  If you are serious about processing very extended spectra then the purchase of IGOR PRO might be a good step anyway, as it is a very efficient, no-nonsense, program for dealing with very large datasets.

       The CAAARS package has been described in:

• I.R.Medvedev, M.Winnewisser, B.P.Winnewisser, F.C.De Lucia, E.Herbst, J.Mol.Struct. 742, 229-236 (2005)

       The DAPPERS package has been introduced and described in:

• N.Love, A.K.Huff, K.R.Leopold, "A new program for the assignment and fitting of dense rotational spectra based on spectral progressions: Application to the microwave spectrum of pivalic anhydride", J.Mol.Spectrosc. 370, 111294:1-7 (2020)

   
        This package was created to deal with the results of the broadband spectra acquired by the NIST auto-scanning FTMW spectrometer.  The package consists of the main jb95 GUI module, and three ancillary programs:

       The LLWP package has been introduced and described in:

• L.Bonah, O.Zingsheim, H.S.P. Müller, J-C.Guillemin, F.Lewen, S.Schlemmer, "LLWP —A new Loomis-Wood software at the example of Acetone-¹³C₁", J.Mol.Spectrosc. 388, 111674:1-10 (2022)

   
        This is an in-house package for dealing with spectra recorded at jpl and promises to do a lot once you find out how to use it. Spectra can be in several different formats, among them simple ASCII two-column frequency,intensity format (called .dat in the input options).

        This package consists of three modules:

        The programs are written in Visual Basic 2005, hence the requirement for Microsoft .NET Framework 2.0. Note that you typically will have to download the: "Microsoft .NET Framework Version 2.0 Redistributable Package (x86)" 22.4 Mb and not, for example, the ".NET Compact Framework 2.0 Service Pack 1 Redistributable" which does not work, even though it implies that it is a Service Pack to the first package.

        The package was first presented at the PRAHA2006 conference.

        The name above is a colloquially used loose description of several seminal programs developed in the Giessen laboratory, jointly with Cologne laboratory (both in Germany).   These predate graphical operating systems but used interactive MS-DOS based graphics for operation.  A still very useful description of the algorithm and features has been published in:

• B.P.Winnewisser, J.Reinstadler, K.M.T.Yamada, J.Behrend, "Interactive Loomis-Wood Assignment Programs", J.Mol.Spectrosc. 136, 12-16 (1989).

        This was the first published Windows program with Loomis-Wood graphical assignment capabilities. Developed for analysis of multistate linear-rotor vibration-rotation spectra, and can deal with the various possible resonances.

        A comprehensive description of INFIA has been published in:

• R.Brotherus, J.Comput.Chem. 20, 610-622 (1999)

   
        This package, as the name implies, is in the form of a set of routines for the versatile IGOR PRO program for graphical analysis of data. It seems to be tailored to be used in analysis of spectra of linear molecules. Considerable effort has gone into documentation of this package. There is a web-based manual, a tutorial, as well as a help file added to the Igor Pro help system. The tutorial ends with a very apt paragraph, which is applicable to all packages compared on this page:

        ... Remember, the Loomis-Wood Add-In is just a tool. At all times, you need to understand what you are doing to get meaningful results. The add-in is not a tool to allow novices to assign complicated spectra. The add-in is a tool to help spectroscopists assign spectra faster with fewer mistakes, since the add-in minimizes the need to manually assign and manipulate line-lists. In particular, do not neglect to examine the actual spectrum to make sure your assignments make sense.

The package was presented at the 2005 OSU Symposium.

        This program comes in two flavours:

        The format of input and output files is configurable so it is possible to combine the programs with different fitting/prediction packages. The default fitting program for LWW is Petr Pracna's SimFit, and the quantisation is J,K,l,v.  LWWa is stated to work with SPFIT/SPCAT, using J,Ka,Kc,v quantisation.

        The package was first presented at the PRAHA2006 conference.

   
        The program promises not only to simulate, but also to fit rotational structure in vibrational of electronic spectra of linear, symmetric and asymmetric top molecules. Interstate interactions can be accounted for, and it appears that pure rotational spectra can also be dealt with. Frequency calibration of

        The package was presented in communication TH12 at the 62nd OSU Symposium, 2007. PGOPHER has also been described in the following journal publications:

• C.M.Western, "PGOPHER: A program for simulating rotational, vibrational and electronic spectra", J.Quant.Spectrosc.Radiat.Transf. 186, 221-242 (2017)
• C.M.Western and B.E.Billinghurst, "Automatic assignment and fitting of spectra with PGOPHER", Phys.Chem.Chem.Phys. 19, 10222-10226 (2017)

        Regrettably the author is now deceased, although the program website (as of 2023) is active.

   
        This module is one of the VMS Draw tools being part of the Virtual Multi-spectral Spectrometer package under development in Pisa. 

        It was introduced in D.Licari, N.Tasinato, L.Spada, C.Puzzarini, V.Barone, J.Chem. Theory Comput. 13, 4382-4396 (2017).