During the late nineties, I was deeply involved in semi-empirical calculations of chemical molecules and their reactions. Very early on, I realized that only a few computer programs of this kind are available on the web and none of them are free. This inspired me and my friend to develop our own program.

I chose the MOPAC7 calculation engine for which the source code was available for noncommercial use. Also, RasWin viewer was used as the visualizing agent in our program package. With the kind help of Dmitriy Litvinov, I've spent a year assembling WinMopac7.21.

Today, 11 years later, this program is still a great tool for semi-empirical calculations on both the professional level and in particular the educational level.

Dr. Roman Shchepin