Hexen
Raven's Watcom DOS source, GPL since 2008, compiled whole.
Hexen runs on PRISM, a C and C++ compiler written in plain JavaScript. ★ Star it on GitHub if you liked seeing it here.
Arguments
PRISM's log
What PRISM says while it runs the program shows here once it is playing.
Source
sourceforge.net / projects/hereticthe program
website
jfrelat-lab / prismthe compiler
GitHub★ Star