ANGLE is a conformant implementation of the OpenGL ES 2.0 specification that
is hardware‐accelerated via Direct3D. ANGLE v1.0.772 was certified compliant
by passing the ES 2.0.3 conformance tests in October 2011. ANGLE also provides
an implementation of the EGL 1.4 specification.

ANGLE is used as the default WebGL backend for both Google Chrome and
Mozilla Firefox on Windows platforms. Chrome uses ANGLE for all graphics
rendering on Windows, including the accelerated Canvas2D implementation
and the Native Client sandbox environment.

Portions of the ANGLE shader compiler are used as a shader validator and
translator by WebGL implementations across multiple platforms. It is used
on Mac OS X, Linux, and in mobile variants of the browsers. Having one shader
validator helps to ensure that a consistent set of GLSL ES shaders are
accepted across browsers and platforms. The shader translator can be used
to translate shaders to other shading languages, and to optionally apply
shader modifications to work around bugs or quirks in the native graphics
drivers. The translator targets Desktop GLSL, Direct3D HLSL, and even ESSL
for native GLES2 platforms.