@Hakime: On the competition with native apps, Dart's plan is making progress (should be significantly more efficient than JS at least with the dedicated Dart VM). But there are other pieces and options to complete this puzzle. The underlying web platform is growing, with new extensions appearing every other week to provide access to new functionality from the GPU to cameras to game controllers to storage etc. Finally, Google's [P]NaCL will enable the full performance of native languages for your finite element analysis, although feature-wise it will be still constrained (access to the same external APIs that JS can use), but this actually converges with the strong trend to put even native applications inside tighter sandboxes with "safer" native APIs, from Android and iOS to Metro/WinRT. A few more years down the road, I think browser apps will be on equal footing at least with sandboxed / AppStore-compatible applications. The browser won't be able to deliver only low-level stuff like a device driver, a machine-level debugger or a virus scanner, but that will be 1% of the market.