FlasCC unfortunately still targets the unportable proprietary Flash stage system.
Emscripten could be perfect here. It is basically a C++ to Javascript compiler but also provides well known C++ media libraries such as SDL, OpenGL, SDL_mixer, SDL_image, Qt, glut etc...
My software always uses either SDL or Glut and OpenGL so it has been very easy to put out a web build. I highly recommend these technologies if you want to keep with C++ but also target the web (as well as every other platform under the sun ;)
https://github.com/kripken/emscriptenA few simple demos using the technology can be found at
http://devio.us/~kpedersen/mutiny/doku.php?id=demos (apologies for the slow server)