I was playing with similar idea. To provide browser-based playground for bitcoin scripts.<p>Technically my approach was different. I used emscripten to compile bitcoin sources into javascript and exposed simple wrapper of its functionality.<p>Interesting excercise, never finished :(<p><a href="https://dl.dropboxusercontent.com/u/559047/bitcoin-emscripten.png" rel="nofollow">https://dl.dropboxusercontent.com/u/559047/bitcoin-emscripte...</a><p><a href="https://dl.dropboxusercontent.com/u/559047/tx-verification.png" rel="nofollow">https://dl.dropboxusercontent.com/u/559047/tx-verification.p...</a>