Exactly what I saw. This isn't a matter of slow server, but some examples are taking way too much ressources. Freezes. In the case of many charts in the scope, as i need refresh every 10 seconds, this will turn in blocking in no time. Testing performances in firefox debugger is already freezing with one chart and no refresh, and i didn't see the garbage collector be significant. (Memory leaks..) Too bad that charts are good. But performances should be a big warning.