The next Fortran standard (Fortran 90) was published too many years after FORTRAN 77 was out, allowing other programming languages to evolve and compete with Fortran. For example, the system-programming language C, and its evolved variant C++, became more popular in the traditional strongholds of Fortran, the scientific and engineering worlds, in spite of being non-computationally oriented.
After many false starts and much controversy, a greatly revised Fortran standard was published by ISO in 1991, known as Fortran 90.