Adds info from current landing page to README file

Also adds a table to document support for various APIs and platforms.

Change-Id: Ie032f553dec23516242a96ce6788fb086fad4229
Reviewed-on: https://chromium-review.googlesource.com/311021
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>
diff --git a/README.md b/README.md
index c85fa82..8815196 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,20 @@
 #ANGLE
-The goal of ANGLE is to allow Windows users to seamlessly run WebGL and other OpenGL ES content by translating OpenGL ES API calls to DirectX 9 or DirectX 11 API calls.
+The goal of ANGLE is to allow users of multiple operating systems to seamlessly run WebGL and other OpenGL ES content by translating OpenGL ES API calls to one of the hardware-supported APIs available for that platform. ANGLE currently provides translation from OpenGL ES 2.0 to desktop OpenGL, Direct3D 9, and Direct3D 11. Support for translation from OpenGL ES 3.0 to all of these APIs is nearing completion, and future plans include enabling validated ES-to-ES support.
 
-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. Work on ANGLE's OpenGL ES 3.0 implementation is currently in progress, but should not be considered stable.
+|                |  Direct3D 9   |    Direct3D 11      |    Desktop GL      |    GL ES  |
+|----------------|:-------------:|:-------------------:|:------------------:|:---------:|
+| OpenGL ES 2.0  |    complete   |      complete       |     complete       |   planned |
+| OpenGL ES 3.0  |     -----     |  nearing completion | nearing completion |   planned |
+[Level of OpenGL ES support via backing renderers]
+
+|             |    Direct3D 9  |   Direct3D 11  |   Desktop GL  |
+|------------:|:--------------:|:--------------:|:-------------:|
+| Windows     |        *       |        *       |       *       |
+| Linux       |                |                |       *       |
+| Mac OS X    |                |                |   in progress |
+[Platform support via backing renderers]
+
+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.
 
@@ -15,8 +28,12 @@
 * Join us on IRC in the #ANGLEproject channel on FreeNode.
 * Read about ANGLE development in our [documentation](doc).
 * Become a [code contributor](doc/ContributingCode.md).
+* Refer to ANGLE's [coding standard](doc/CodingStandard.md).
+* Learn how to [build ANGLE for Chromium development](doc/BuildingAngleForChromiumDevelopment.md).
+* [Choose an ANGLE branch](doc/ChoosingANGLEBranch.md) to track in your own project.
 * File bugs in the [issue tracker](http://code.google.com/p/angleproject/issues/list) (preferably with an isolated test-case).
 * Read about WebGL on the [Khronos WebGL Wiki](http://khronos.org/webgl/wiki/Main_Page).
 * Learn about implementation details in the [OpenGL Insights chapter on ANGLE](http://www.seas.upenn.edu/~pcozzi/OpenGLInsights/OpenGLInsights-ANGLE.pdf) and this [ANGLE presentation](https://code.google.com/p/angleproject/downloads/detail?name=ANGLE%20and%20Cross-Platform%20WebGL%20Support.pdf&can=2&q=).
 * Learn about the past, present, and future of the ANGLE implementation in [this recent presentation](https://docs.google.com/presentation/d/1CucIsdGVDmdTWRUbg68IxLE5jXwCb2y1E9YVhQo0thg/pub?start=false&loop=false).
-* If you use ANGLE in your own project, we'd love to hear about it!
\ No newline at end of file
+* If you use ANGLE in your own project, we'd love to hear about it!
+