Oh man, I thought "Canvas" was the name of yet another web framework, but no, they mean the actual HTML <canvas/> element.

Back in university, I was tasked to build a calendar view with HTML. It was my first web project, I decided to use a canvas to draw the calendar.
It took me several times as long to complete my implementation compared to other students, because I had to re-implement layouting, click handlers and probably more things I don't remember...