My "Hello World" for HTML5 Canvas. We don't do much here except to draw a few rectangles, but you gotta start somewhere!
A few things to notice here: when you look at the code itself, we don't "create a rectangle and fill it with a color." Instead, we set the current fill value and the current stroke value for the canvas context itself. This is similar to GIMP and Inkscape where the program itself keeps track of the current foreground and background colors, etc.