Next version of Qt may use the V8 JavaScript engine
V8 is a JavaScript engine created by Google for the Google Chrome browser. While Google Chrome uses the WebKit engine, it replaces WebKit’s engine with Google’s own giving WebKit a huge boost in speed. Google has made constant tweaks and enhancements to their engine – the current version being 3.3 – due to which it still remains the fastest JavaScript engine among current browsers.
Now it seems likely that Qt, which too includes the WebKit browser-engine as QtWebKit, will replace their JavaScriptCore engine with V8. Qt developers have been looking into this for a while now, and the benchmarks have shown that such a replacement could have huge benefits.
Qt uses JavaScript not only in the browser component, but also in their support for scripting applications via QtScript. Additionally, QtQuick and QML use JavaScript heavily as a means to create and script declarative UIs.
With the V8 engine behind all of these, there could be significant improvement in performance for Qt applications that take advantage of these features. A good example of this would be KDE, which uses all three heavily.