[NewsPoster]

As it has done each fortnight, Apple on Wednesday updated its developer-intended Safari Technology Preview, which is an alternative version of the present Safari desktop browser for OS X that offers some advanced -- but still buggy -- JavaScript, CSS, and HTML5 technology that will be incorporated into future versions. The new version, the sixth beta, includes another lengthy list of JavaScript/ECMAScript improvements and support for next-version draft specifications, along with improvements to CSS, Web APIs, and media handling.

Among the changes in JavaScript are improve RegEx matching in large result arrays, and improved integer-to-float conversion code generation in the B3 JiT Compiler, along with better error handling and various performance tweaks including improving TypedArray access by 30 percent in the low-level 64-bit interpreter. For CSS, support has been added for normal keyword value -- per the draft CSS Box Alignment Module Level 3 spec, and the parsing of CSS Grid's fixed-size has been updated to the same draft specifications.

Among the Web APIs and Web Inspector, STP beta 6 started allowing empty strings in the FontFace constructor and allowing custom drag-and-drop even without placing data in the clipboard, but stopped firing a popstate event with a null state when navigating back to a stateless cached page. The Web Inspector fixed a regression that involved CSS properties modified via JavaScript, improved garbage collection time by double when recording heap snapshots, and improved the loading time of Web Inspector, among many other fixes and tweaks.

With media handling, the update fixes scrolling on iTunes Connect pages, fixed a regression that broke zooming in (using command-plus) on pages, and reduced flicker and jumpiness when entering and exiting fullscreen presentation mode, along with a fix to auto-correction that makes it easier to type contractions and email addresses. Although the software is still in development, has numerous known flaws, and is intended for developers, it is available for public testing directly from Apple's website, and can be tested alongside the current stable release of Safari and other web browsers (though users have the option to make STP the default browser if they wish).

Frankly Apple could make the current public release of Safari a technology preview with its GPU glitches on Google services such as Maps and YouTube (e.g., sometimes crashing/freezing after full screen, not properly showing all text or street view map data upon waking from sleep).

[Charles Martin]

I can't say as I've ever experience that on my 2012 MacBook Pro (which has pretty far from the sportiest graphics card) in typical use, but then I rarely go immediately into Maps from sleep, or have the unit already in Maps when asleep, so perhaps this is a thing. Have you tested this on a variety of Macs to confirm its not just you/your machine?

Concerning YouTube and HTML5: https://discussions.apple.com/message/29440022

Presumably with HTML5-based Maps (since Google's transition away from Flash for street view), a similar bug exists.

[rtamesis]

Websites that heavily use Javascript can bring Safari on the iPad down to its knees. I often have to turn Javascript off in order to view those websites. Will this new Safari fix it?