@tshepang @servo My understanding is that rendering of web pages happens in four steps: Style (compute effective css properties of every element), layout (compute the location and size of every element), paint (draw the individual elements) and composite (composite the painted elements to present to the user). Stylo only handles the style step. Floats were already supported in this step by Stylo, but Servo didn't support it in the layout step for their new layout engine yet.