In addition to
general tuning throughout the product, we've specifically improved
performance in the Chakra JavaScript engine with memory
optimizations in functions and deferred parsing for event handlers, as well as optimizing
performance for common JavaScript APIs like frame.contentDocument, iframe.contentWindows, scriptElement.src, and requestAnimationFrame, and dramatically reducing callback overhead, for a better experience with many of the most popular frameworks and coding patterns we see in the wild.