F is a subset of Fortran 95.
F homepage: https://pages.swcp.com/~walt/F/
The F syntax is available at http://pages.swcp.com/~walt/F/F_bnf.html
Since F is a subset of Fortran 95, any Fortran 95 compiler will compile an F program. However, to impose strict F syntax, a compile with explicit support for F can be used.
The G95 compiler supports the F standard and will enforce the standard when -std=F
is used:
g95 -std=F my_program.f95