I makes no sense for people to have moved to C for things that have recently appeared in Fortran. What are the features they've been missing which have appeared in Fortran in the last 10 years?

So why is NWChem being re-written in C++, and what relationship does that have to exascale? Richard O'Keefe said 10 years ago ago "Why not start by rewriting the Fortran code _in_ Fortran? Fortran 90 is a very pleasant language." (NWChem is just in Fortran77 as far as I remember.)

I work in HPC, though I don't write numerical code these days, but I'd definitely prefer to write it in Fortran than C, and I'm not clever enough to use C++. I'd also much rather maintain typical scientific Fortran.