Home Page:
http://www.openwatcom.org/
Donate and Download page
http://store.scitechsoft.com/product_info.php?products_id=37
OpenWatcom is an open source release of the Watcom C, C++, and Fortran compilers. Michal Necasek has an article describing how to set it up.
http://pages.prodigy.net/michaln/os2/Watcom11c.html
Source: OS2.jp