F'77 added arbitrary lower bounds on arrays, including explicit-shaped and assumed-shaped dummy arrays. It is a useful and portable feature, though somewhat confusing to newcomers when they try to pass an array with non-default lower bounds as an actual argument and they don't work as one would expect.

F'90 added arbitrary lower bounds on assumed-shape dummy arrays, as well as on allocatables and pointers. Still pretty portable, though more confusing cases were added. F'2003 then added automatic (re)allocation of allocatables, and the results continue to astonish users. And only two compilers get them right, so they're not portable, either.

Ada's array indexing is part of its type system. Fortran's is not (for variables).