GNU M4 v1.4.17 had been ported to OS/2-eCS (2014/07/18).
http://hobbes.nmsu.edu/h-search.php?key=m4-
"GNU M4 is an implementation of the traditional Unix macro processor. It is mostly SVR4 compatible although it has some extensions (for example, handling more than 9 positional parameters to macros). GNU M4 also has built-in functions for including files, running shell commands, doing arithmetic, etc."
Official Project page: http://www.gnu.org/software/m4/
If you would like to support KO Myung-Hun you can make a donation at his website.
Port by: KO Myung-Hun