WebKit 3D CSS transforms coming to Snow Leopard, not Leopard

Apple plans to bring support for its proposed 3D CSS Transforms—already a W3C working draft—to Snow Leopard, but may be leaving Leopard in the dust. Apple already has support for the proposed standard in WebKit, though currently it is only enabled in Mobile Safari, the browser included on Apple’s mobile devices.

Earlier this year, we told you about the rather clever CSS-based, three-dimensional perspective transforms that Apple added to WebKit, extending an earlier two-dimensional concept that enables some rudimentary animation when controlled via JavaScript. The transforms include skewing, scaling, rotating, and positioning of 2D objects within three-dimensional space, and take advantage of 3D hardware acceleration. Using CSS as the basis for defining the transforms makes it relatively easy for Web designers and developers to take advantage of the effects without complicated 3D programming.

Support for two-dimensional transforms has been enabled in Safari 4, but so far only Mobile Safari supports the 3D variants. Apple demonstrated the 3D transforms as a feature of Safari 4 during this year’s WWDC, but the shipping versions for both Leopard and Windows lack the support. Comments from Apple employee Simon Fraser indicate that full support of the 3D transforms is enabled in nightly WebKit builds, but (so far) only for Snow Leopard. His comments also seem to suggest that support for Leopard may not be forthcoming.

The issue is not hardware compatibility—if it can run on a 412MHz ARM processor with a rather (by desktop standards) paltry GPU core, any machine that can run Leopard is capable of taking advantage of the transforms. Leopard is certainly capable of supporting the feature from a software perspective, too. No one at Apple would comment on why the feature isn’t enabled for Leopard or when support might be coming.

Clearly Apple intends for the standard to be adopted for CSS and to enable more visually rich Web-based applications. And, while Snow Leopard’s low price is designed to encourage quick adoption of Snow Leopard, the numerous PowerPC-based Macs won’t be able to take advantage of the upgrade. It should be noted that Firefox 3.5, released today, includes support for Mozilla’s implementation of CSS Transforms on Mac OS X (including Leopard), Windows, and Linux. Creating an artificial disparity of support between versions of Mac OS X only creates an unnecessary stumbling block for the standard to become more widely adopted.