SOURCE CODE
The game engine is doomgeneric (a port of Chocolate Doom / the GPL-released Doom source), licensed under the GNU GPL v2. We modified it: a stats export for the points overlay (rk_stats.c), a browser platform layer (rk_web.c), cheats compiled out, Freedoom strings built in, no busy-waiting in the browser.
The zip has the full engine source we compile (engine/src, engine/build.sh, Emscripten), the WAD tools and the pixel art code. Game data is Freedoom: Phase 1 0.13.0 (BSD licence, © Contributors to the Freedoom project) with our own art merged on top.