Java applets were unfortunately ahead of their time for the hardware available and got a bad reputation for being slow, along with security problems, and now that Google extinguished plugins like Java and Flash (Google gets to skip the Extend step) we're stuck with whatever Chrome lets webasm do with no competition for this kind of VM-in-a-browser. The homogenization Google forced on the web is a travesty but everybody is too distracted by shiny new HTML5 features and the anti-plugin bandwagon to care.