WebGL[1] is a standard specification currently being developed to display 3D graphics in web browsers. It enables hardware-accelerated rich 3D graphics in web pages without the need for special browser plug-ins, on any platform supporting OpenGL 2.0 or OpenGL ES 2.0. Technically it is a binding for JavaScript to native OpenGL ES 2.0 implementation, to be built in to browsers. WebGL is managed by the non-profit technology consortium Khronos Group.
WebGL grew out of the Canvas 3D experiments started by Mozilla. Mozilla first demonstrated a Canvas 3D prototype in 2006. By the end of 2007, both Mozilla[2] and Opera[3] had made their own separate implementations. In early 2009 Mozilla and Khronos started the WebGL Working Group.

The WebGL Working Group includes Apple, Google, Mozilla, and Opera, and WebGL is already present in nightly builds of Mozilla Firefox 3.7[4], Firefox for mobile 1.0, WebKit[5], and Google Chrome developer previews[6].

Some libraries in development which are incorporating WebGL include GLGE, C3DL, WebGLU (and SceneJS).

It uses the canvas HTML element.

Example Text is copied from: http://en.wikipedia.org/wiki/WebGL