Instead, a program is typed and saved with an editor (i.e., a word processor), and the program is then turned into an executable file by a Fortran compiler. Unlike in Basic, a Fortran program is not typed in a "Fortran window". Moving from QuickBasic to Fortran is more a matter of change of terminology than anything else. Even though this semester we have thus far studied Basic, at the same time we have studied Fortran, because commands and procedures are very similar in the two languages. (The number denotes the year of introduction.) Fortran 77 is probably still the most used, and it is the version installed on UHUNIX and in the UH math lab. There are several versions of Fortran around, among them Fortran 77, Fortran 90, and Fortran 95. The name Fortran originally referred to "Formula Translation", but it has long since taken on its own meaning. Part of the reason for Fortran's durability is that it is particularly well-suited for mathematical programming moreover, there are millions of useful programs written in Fortran, created at considerable time and expense, and understandably people are reluctant to trash these old programs and switch to a new programming language. Fortran is one of the oldest programming languages devised, but it is also still one of the most popular, especially among engineers and applied scientists.