Wouldn't that be too taxing on battery life? I'd rather have WebGL used for 3D games or visualizations where I at least know the impact beforehand rather than like flash or as a CSS animation alternative.

That's a good point. I've never compared the battery usage. But you don't have to make everything 3D (I think). I think you can use WebGL in a 2D context and the battery impact is probably less significant.

Mostly, I just want to avoid learning each mobile platform just to make one app. That's been turning me off from mobile development for years. I'd rather use something like Cordova with webgl and hit all mobile platforms in one shot.

I've never heard of "WebGL in a 2D context". WebGL is WebGL is WebGL - it's a WebGL context. Whether or not you decide to feed it drawing commands that will end up looking like a 3d object or like a 2d sprite is up to you.

I was thinking of a 2d canvas context. Basically, I would expect battery consumption to be lower when WebGl is rendering 2d than it would be if it were rendering 3d. It just seems intuitive that 3d requires more computation. But I really don't know. I've never seen any battery usage comparisons.

the browser may be able to optimize the 2D canvas operations by using the GPU more efficiently, but drawing with the webgl stack is going to suck the same amount of battery whether doing 2D or 3D. After all, 3D is really just correctly positioned 2D triangles.

It would be interesting to see what the impact would be in a more limited context as you suggest. Also, having it as part of a toolkit would lessen the burden and allow for continuous optimization. Exciting times!