I have been experimenting with the emscripten C to JavaScript compiler. I have used it to compile the Gambit interpreter into JavaScript. This allows the Gambit interpreter to run in the browser! Just direct your browser to
http://feeley.github.io/gambit-in-the-browser
Be patient... it can take 30 seconds to a minute to load the page (there's about 11 MB of JavaScript code). Use a fast JIT based browser if possible (Firefox or Chrome have been tested).
Marc