The IUMSC, like many crystallography laboratories established in the 1960's, obtained programs from other laboratories as well as developing specialized programs to solve, refine, and present molecular structures from X-ray data. There were several major sources for the software used in the XTEL library. The most significant were:

• LANL library, including GENLES (general least squares), FOURIER (as the name implies), and most importantly, the elegant space group interpretation routines written by Dr. A.C. Larson of the Los Alamos National Laboratory. These programs perhaps have had the most influence on the XTEL library.
• Oak Ridge National Laboratory was responsible for development of may of the early least squares, Fourier, and other programs.
• ORTEP, the Oak Ridge Thermal Ellipsoid Plot program written by Carrol Johnson. One of the programs developed at Oak Ridge, is probably the most under-cited program ever used in chemistry. The original ORTEP has undergone many modifications over the years. It is the basis for most of the plotting programs in use in the IUMSC, as well as the basis for several other local programs such as SHORTEP and AVOID.
• Brookhaven National Laboratory was another source for major modifications of many of the early "core" programs.
• Finally, the continuing efforts of Prof. James Ibers of Northwestern University must be acknowledged when discussing the basic core programs in crystallography. Many of the programs (including those from Oak Ridge and Brookhaven) in use in the IUMSC have roots in his laboratory.

Proprietary code and commercial programs

While much of the code used in the IUMSC is public domain, some routines and software were specialized enough that it was more expediant to use commercial software. The following commercial code is utilized in various portions of the library, and must be purchased by users who want to implement the entire XTEL library.

• No Limit Fortran routines by MEF Engineering. These routines were incorporated in the diffractometer control software used in the IUMSC. As nearly as we can tell the company no longer is in business.
• ACROSPIN is a neat (and inexpensive) little DOS program that allows a collection of vectors to be rotated in real time. Available from Acrobits, USA (David B. Parker); (800)ACROBITS or (801)966-2580. Acrospin files are created by COMORT and CRYSTAL in the XTEL library.
• Opt-Tech Sort, by Opt-Tech Data Processing is the sort utility used in the data reduction phase of the structure analysis package. Presumably any similar program could be substituted. The DOS SORT.COM would not handle large enough files.
• Media Cybernetics Halo graphics software is used in the graphics programs in the IUMSC. These routines were (and still are) used to allow VGA resolution on DOS systems, and to generate hpgl and other format hard copy output. Efforts are now underway to convert all XTEL software to avoid the use of the Halo drivers since they cannot be purchased except as a package and are not terribly easy to install and use. Versions of most of the graphics programs which do not use the proprietary graphics routines should be available by early 1996.

Availability of XTEL code