Open Watcom 2.0 f77 (2014/01/14) is available for download on the OS/2-eCS platform.
"Open Watcom is a project of the open source community to maintain and enhance the Watcom C, C++, and Fortran cross compilers and tools."
It is open source software under the Sybase Open Watcom Public License version 1.0.
URL: http://www.openwatcom.org, http://open-watcom.github.io/open-watcom/