Websocket-hatena-syntax-editor is a project mainly written in JAVASCRIPT and COFFEESCRIPT, it's free.
realtime compiler for hatena syntax
This is hatena syntax editor and updater.
using: hatena word processor http://tech.nitoyon.com/javascript/application/texthatena/wordpro/
need : node(npm) :
exec: $ coffee app.coffee 3000
open http://localhost:3000 (only tested Chromium 2011-8-11)