Apple’s dev edition Safari brings future WebKit to your Mac

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Safari will be kinder to MacBook Pro battery life.
Safari will be kinder to MacBook Pro battery life.
Photo: Apple

You can get a taste of the future of Safari on the Mac today, thanks to the release of the new Safari Technology Preview from Apple that gives regular users and developers an easy way to test new features and improvements that are coming soon to the web browser.

The new stand-alone app for OS X can be downloaded and used for free by anyone, and includes a cutting-edge version of the WebKit browser engine that is still in development. It’s a great way for web developers to get ahead on new features by testing them before they’re public.

Safari Technology Preview can be used side-by-side with the regular version of Safari to test for behavioral issues. It also includes new improvements for Web Inspector.

Here’s a list of the new features:

ECMAScript 6
Safari Technology Preview supports ECMAScript 6, the latest iteration of the JavaScript programming language. ES6 has many new features, including classes; lexical scoping using let, const, and class; iterators and generators; arrow functions; default parameters values; and many new built-in APIs.

B3 JavaScript JIT compiler
B3 is a new low-latency, high-throughput compiler designed from the ground up to support JavaScript and other dynamic languages. B3 delivers great performance benefits, especially on systems with fewer CPU cores.

Improved IndexedDB implementation
WebKit’s revamped IndexedDB implementation is more stable, more standards compliant, and still undergoing rapid improvement.

Shadow DOM
The latest version of Shadow DOM has been heavily revised based on input from web content authors and browser developers. WebKit is the first engine to implement this new version.

Programmatic cut and copy to the clipboard
It’s now possible to programmatically copy and cut text in response to a user gesture with document.execCommand(‘copy’); and document.execCommand(‘cut’);. Having this ability may eliminate some websites’ last need for the Flash plug-in.

Content Security Policy Level 2
You can define a policy for your web application to mitigate content injection vulnerabilities, such as cross-site scripting (XSS). Level 2 expands on Level 1 with support for