With emscripten installed:
$ emcc -s ASM_JS=1 raycast.c -o raycast.js --preload-file textures
$ python -m SimpleHTTPServer
Open up localhost:8000 in your asm.js-enabled browser.
avik-das/emcc-raycast
A C/SDL-based raycast renderer that can be compiled to asm.js to run in the browser
C