Preview at WWDC likely in June, followed by September launch.
Apple Launches 'Safari Technology Preview' Browser for Web Developers
According to TechCrunch, Apple's goal with Safari Technology Preview is to gather feedback from developers on its browser development ahead of launch through a method that's more easily accessible than WebKit.
- ECMAScript 6 support including lexical scoping, iterators, generators, arrow functions, default parameter values and many new built-in APIs
- Better standards compliant IndexedDB support with more stability
- Added the ability to use
document.execCommand('cut')in response to a user gesture to copy and cut text programmatically
- The latest implementation of the Shadow DOM specification
- Added support for Content Security Policy Level 2
Web Inspector Changes
- Included many web compatibility fixes and bug fixes