During my work and even in my spare time I write the occasional computer program. They are not very sophisticated in general, but they do what they are supposed to do. The programming language of my choice is Fortran 77. It is easy to learn and quite useful as well. In my field of work it is one of the most common programming languages.
Fortran is highly portable and compilers are available for almost any platform: Windows, OSX. It is usually available for Linux using g77 in your terminal. For UNIX the command is f77.
Software by Lemmus is povided without warrenty. Limited support is available. Just E-mail me. Currently, all the software is open-source. However, limitations on redistribution may apply. The software is free, but you are asked to refer to this website if you publish any results obtained (directly or indirectly) as a result of using my software.