Does anyone ever use the canvas API or WebGL?

Although it exists, is it really ever used in development and production?

Of course. Anytime you see a drawing board, it will use canvas. Glitch for example uses canvas so that you can draw on it while your project is loading.

WebGL is pretty common as well. Anytime you see 3d objects in your browser that’s not an picture, it’s probably using WebGL. Here are real examples.