Fortran is still going strong. At a High-Performance Computing seminar I attended a few years ago, the speaker said that around 50% of high performance computing applications are written in Fortran (you know, these shiny little programs that can hog a million CPUs for a few hours or weeks or months). The other half being mostly C and C++.

However, programming in Fortran is uncomfortable. Just like programming in C. The advantage of Fortran over C in High-Performance Computing is that it's less uncomfortable to write maths and things with arrays in Fortran.

If you ever need to handle enormous arrays without breaking a sweat or solve systems of equations with hundreds of thousands or millions of variables, you can give Fortran a try. The syntax has come a long way since FORTRAN 77.

Fortran's strength has always been speed. In the early days most Fortran programs would run faster than C programs. The trick is to intentionally leave out features that bloat the language such that all there's left in the language can easily be optimized by the compiler. Only after the C99 standard (I think), C caught up to Fortran in most applications due to stricter aliasing rules.