There's a bunch available.
Try this for additional info:
Fortran 77/90/95 Compilers for Windows and Linux
16 October 2009
G95 is an open source Fortran 95 compiler.
...most of the ISO Fortran 95 standard has been implemented. Platforms supported include Linux(x86, Intel IA64, AMD x86_64), Windows, Macintosh OS X, FreeBSD, Sparc Solaris and HP-UX.
Gfortran - the GNU Fortran Compiler
gfortran, part of the GNU Compiler Collection, is a free Fortran 95/2003 compiler. Like all things GNU, it comes with source code. Precompiled binaries (executables) are available for Windows, Linux, Mac OS X, the old Mac OS (PPC), etc.
Salford FTN95 Fortran 95 Compiler
Salford FTN95 is a Fortran 95 compiler that supports Fortran 77, Fortran 90 and Fortran 95. The compiler generates exectuables for Win32 (but Win32 console and GUI applications) and the Microsoft .NET framework.
There are a lot more.