Erlycomet is a project mainly written in Erlang, it's free.
Mochiweb: rev. 47 (beam files are in priv/ebin)
1) install dojo, dojox and dijit (from SVN) into demo-docroot (because it won't work with dojo from AOL CDN)
2) apply this patch todojox.sketch.UndoStack.add:
+++ UndoStack.js @@ -78,6 +78,9 @@ } }; //console.log('dojox.sketch history add',state);
this._steps.push(state);
this._undoedSteps = [];
},