Like CardDeck, Popup is template driven - you define the appearance of a Popup via a template. With templates, no DOM elements are created for the popup when the page is loaded. Instead, DOM elements are only built when needed, i.e. when the user clicks on the button. So performance is good.

Of course, like all Jitsu controls, Popups support databinding and has a range of other features, like auto-positioning the popup.