More than 3 years on, Opera have released a public preview build of their browser, with a standards-based 3D canvas implementation using WebGL for Windows. In 2007 they had released a preview build showing an implementation of a 3D canvas context.
Opera have been working on a WebGL implementation since early 2009, when the standardization process started. Due to frequent changes in the standard, it had been difficult to commit to a WebGL implementation; but now that it has matured and stabilized, Opera felt it was the right time to release a public implementation of the standard within their browser.
For those who have never heard of WebGL, it is a context to the canvas element which gives you hardware-accelerated 3D rendering in JavaScript. The API is based on OpenGL ES 2.0, which means that it is possible to run WebGL on many different devices, such as desktop computers, mobile phones and TVs. More information can be found here at the Khronos wiki.
The Hardware acceleration in this build is a bit different from what other browsers are doing. Much like IE9 and Firefox 4, do full hardware acceleration of all draw operations - but then, unlike those browsers, who only offer this acceleration on Windows Vista and Windows 7, the implementation will run on any OS with sufficient hardware support. This means full hardware acceleration can be achieved on Windows XP, Linux, Mac OS X and OpenGL ES 2 capable devices such as recent smart-phones and web-enabled TVs.
You can grab the preview build here, and please note that this requires an OpenGL 2.x compatible graphics card and related drivers for hardware acceleration and WebGL to work.
Also, Tim Johansson notes on the Opera Developer blog some limitations; "Neither WebGL nor hardware acceleration will be included in the upcoming release of Opera 11.10 for desktop. Some other aspects, such as SVG rendering, may not work correctly. We will continue working on these new features – fixing on all remaining bugs and optimizing our code – and we will release further preview builds to keep you up to date with our progress."