Edge, Microsoft's browser replacement for IE, has been quick to drop the legacy technologies and just as quick to embrace the new stuff. The lastest new technology to make it into Edge is asm.js and there is a nice proof of principle that it is indeed faster.
"It (asm.js) applies constraints such as static typing to enable opportunities for optimizations, such as type specialized compilation without bailouts and ahead-of-time (AOT) compilation. These optimizations allow asm.js code to have near-native performance and predictable behavior. "
Microsoft introduced support for asm.js back in June as a preview but now its supported by default in the latest Edge.
You can also try the demo out on other asm.js supporting browsers - Firefox and even Chrome.
The support for asm.js has been built into the Chakra engine which Edge uses. However, as well as Edge Hosted Web Apps, and Universal Windows Platform apps that use the WebView control also use Chakra and hence they too support asm.js.
You can try the Chess Battle demo out in a lightweight WebView sample app and see the same advantages of asm.js.