Facebook open sources “Pop” animation engine

Posted Apr 28, 2014

Facebook has announced today that is has open sourced Pop, which is the engine behind Paper’s smooth animations and transitions. It was open-sourced on

Pop uses dynamic animations rather than static animations to control scrolling, bouncing, and unfolding effects in its social news app.

Kimon Tsinteris, a software engineer at Facebook that co-founded Push Pop Press, points out that iOS always excelled at supporting static animations. ?The Apple-provided Core Animation framework makes linear, ease-in, ease-out, and ease-in-ease-out animations simple to leverage,? stated Tsinteris. ?With Pop, we are able to keep the familiar and powerful programming model of Core Animation while also capturing a gesture?s velocity and better reflecting user intent.?