Hold down the mouse button to draw in the rectangle below.
This is a very old demo I built a long time ago. Most of the code is terrible, but I wanted to focus on creating an application where users could draw on a Canvas collaboratively. I wanted to focus on the most basic mechanics. In this example, I just simple ajax button calls. I used to have a more advanced demo with colors and websockets.
Click and drag the mouse on the canvas to draw. Click save to make your lines available for other users to load. Click load to add the lines other users have created to your drawing.