An Internet Explorer 11 preview is included in the recently launched Windows 8.1 Preview
One new feature of Internet Explorer 11 is support of WebGL:
This means Microsoft has backed down from their previous stance
that allowing webpages programmatic access to the GPU was bad for system security.
At this stage the WebGL support is marked experimental and is only version 0.9. Unfortunately no GL extensions are listed so IE only supports stock WebGL, but hopefully Microsoft will add more features before the final release.
It is well known that IE uses Direct2D and Direct3D 11 to render webpages so it appears Microsoft have implemented something similar to the ANGLE project (used by default in Chrome and Firefox on Windows) to compile GLSL into HLSL shaders.
Microsoft have created two new WebGL demos on their IE Test Drive website:http://ie.microsoft.com/testdrive/Performance/Levitation/http://ie.microsoft.com/testdrive/Graphics/LookAround/
I have tested various other WebGL demos around the net and it is a bit hit or miss if they work. Some don't load, and others have graphical artefacts. It appears Microsoft has a lot of work to do to get the WebGL support complete.