I recommend you to keep sources in gist.github.com.
1. Create a new gist with index.html (sample #4772996).
2. Reference it in via hash http://cmx.io/edit/#4772996
3. Publish the gist via http://cmx.io/#4772996
Note: I can't write your changes back to gist,
you have to copy&paste final work to gist yourself!
Please make sure that
The Comix Editor was tested under Chrome. It uses some webkit-specific tricks.
It is a prototype. Currently it is broken under Firefox, Opera and IE.
Interested in porting it to your favorite browser? Check out the sources.