I stumbled upon Google Native Client today. It looks really interesting and you can see why Google seems to be targeting their technologies for the Chrome browser first (link with regards to Dart, their future of JavaScript; quote: “We will strongly encourage Google developers start off targeting Chrome-only whenever possible as this gives us the best end user experience.” – Mark S. Miller).
Try out the example apps. Its surprisingly easy to get started. On OSX, you can see that when running the Pi example, the Native Client module is using quite a whole load of CPU time (in Chrome, do Window -> Task Manager).
In all that, I learned about Google Chrome’s about:flags. You need to enable Native Client support and restart Chrome to get this all working. There’s a fairly good about:flags resource; clearly lots more things to play with there (and helps me understand what the idea being the ChromeOS/Chromebook is now).