Hardware acceleration believes to offer faster performance, lower battery consumption, and new features that would be otherwise impractical. And Opera uses hardware for quite a few things including font display, CSS effects, Canvas 2D graphics, and WebGL 3D graphics.
And, Opera 12 will reach the still very strong Windows XP users, with a few features disabled.
For more detail about Opera 12 alpha and to download it, please visit this this Opera blog page
UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:7.0.1) Gecko/20100101 Firefox/7.0.1
