Apple launches the Safari Technology Preview to test new web technologies

Apple is launching a new version of its Safari web browser aimed squarely at developers. The Safari Technology Preview will allow developers to take a look at web technologies that will be making their way to Safari on OS X and iOS. Apple hopes that developers will use the Safari Technology Preview to experiment and offer feedback to Apple at a faster pace.

Unlike nightly WebKit builds, the Safari Technology Preview is signed and validated by Apple, and works with iCloud. Apple says that the initial version of Safari Technology Preview contains the following features:

• ECMAScript 6: Apple says this is one of the most complete implementations of ECMAScript 6 (ES6), the latest version of JavaScript. ES6 offers support for classes that allow developers to use the object-oriented principals in their JavaScript code, iterators, and new APIs.
• B3 JIT JavaScript Compiler: B3 is a new low-latency, compiler designed from the ground up for JavaScript. B3 optimizes for speedy initial compile times while optimizing the compiled JavaScript for sustained performance.
• Updated IndexedDB Implementation: IndexedDB lets developers store lots of structured data on the client and access that data quickly. Developers have asked for an improved implementation, so Apple released this revamped IndexedDB implementation that is more stable and more standards compliant.
• Shadow DOM: Shadow DOM makes it easier to build large-scale web applications by allowing developers to expose elements on a webpage and defining how they interact with their application. WebKit is the first browser engine to implement this latest version.
• Support for programmatic cut and copy to the clipboard and Content Security Policy Level 2.

The Safari Technology Preview is free to download for everyone, though it's aimed at developers. It requires the latest version of OS X El Capitan, 10.11.4, in order to run.

Check out the Safari Technology Preview