G95 is a stable, production Fortran 95 compiler available for multiple cpu architectures and operating systems. Innovations and optimizations continue to be worked on. Parts of the F2003 and F2008 standards have been implemented in g95.
Open Source Watcom / OpenWatcom Fortran Compiler
The Watcom (now OpenWatcom) Fortran 77 compiler is now available free of charge, complete with source code. This compiler, which generates code for Win32, Windows 3.1 (Win16), OS/2, Netware, MSDOS (16 and 32 bit), etc, was a
well-known compiler some years back (until Sybase terminated it).
MinGW'S G77 (GNU Fortran)
This system comes with the GNU G77 Fortran compiler (among other things, including a C/C++ compiler), which you can use to generate Win32 executables from F77 code. Like many systems based on the GNU tools, Mingw32 comes with
complete with various programming tools, such as a program maintainence program (ie, make), text processing tools (sed, grep), lexical analyser generator (flex), parser generator (bison), etc.
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