This is well worth a read, regarding FORTRAN
FORTRAN is rightfully credited with popularizing the compiled high-level language, but it’s been oddly tricky to find the first implemented compiler. FORTRAN uncontestedly released the first commercially available compiler in 1957. But in 1952, Grace Hopper wrote one for the A-0 system and Alick Glennie wrote one for his Autocode. It appears that part of the debate is on what counts as a compiler beyond turning source code to machine code. For example, the A-0 system’s compiler was said to act more like a “loader or linker” in today’s term. Unfortunately I know almost nothing about compilers so I’m lost.