Fortran has been around now for near 70 years. It’s hard to imagine a piece of technology surviving for that length of time, but Cobol has done the same. How have they achieved this? In part it is because they are living languages, going through periodic revisions in 5-10 year cycles, and evolving.
Fortran 77 evolved to Fortran 90, then to 95, 2003, 2008 etc. All these revisions updated the core languages structures, whilst maintaining backwards compatibility. Some such as Fortran 2003 added a new paradigm into the mix – OO. Features like free-formatting were added, and the reliance on legacy jump instructions like the arithmetic IF were reduced, or removed altogether. Languages like C are also living languages, but the basic context of structured programming has changed little since it’s inception, so changes are usually of the incremental kind, and never really that radical. The evolution of languages should be a very organic process, with modifications reflecting the current needs of the programing community, and the inability of the language to perform what is required of it.