After reading about Tangle I was excited about real-time interaction with code and documents but having to write javascript seemed like a pain. Fangle is an alternative way (to html/js) to create reactive documents.
If you are interested in using fangle you can fork it on github.
If you've looked at the source code and would like to scold me for how ugly it is feel free to submit issues or send pull requests.
All code is released under the supplied (MIT) license unless otherwise stated.
While I was working on tangle I ran across tangledown which is similar is some ways. If you're interested in creating interactive documents from plaintext it may interest you as well.